Readme cleanup (#154)

* Initial cleanup

* Lint

* Abbreviate `cmd`, revise "change cell type" binding description to follow JL and revise `Shift` description

* Reorder key bindings so that corresponding Edit mode and Command mode bindings are in the same order

* More fixes

README.md

@@ -16,14 +16,14 @@ Notebook cell vim bindings
 
 ## Modes
 
-Like vim, Jupyterlab has a distinction between edit mode and command mode. Jupyterlab Command mode is when the cursor is not in a specific cell, and edit mode when typing in a cell.
+Like vim, Jupyterlab has a distinction between Edit mode and Command mode. Jupyterlab is in Command mode when the cursor is not in a specific cell, and it is in Edit mode when typing in a cell.
 
-This extension combines the Jupyterlab (Edit and Command) modes with the standard vim modes (Normal, Insert, Visual). So the set of modes now looks like:
+This extension combines the Jupyterlab (Edit and Command) modes with the standard vim modes (Normal, Insert and Visual). So the set of modes now looks like:
 
-1. Jupyterlab Command Mode
-2. Jupyterlab Edit Mode
-   - Insert
+1. Jupyterlab Command mode
+2. Jupyterlab Edit mode
    - Normal
+   - Insert
    - Visual
 
 See [key bindings for switching between modes](#switching-between-modes).
@@ -44,66 +44,66 @@ mamba install -c conda-forge jupyterlab_vim
 
 To learn how to modify key bindings see the [modify-keybinds.md](modify-keybinds.md) file.
 
-**Please note that all keys are lowercase unless `Shift` is explicitly indicated.**
-For example, `Y, Y` is two lowercase `y`s, `Shift-Y, Y` is one uppercase `Y` followed by a lowercase `y`.
+**Please note that all keys are lowercase unless <kbd>Shift</kbd> is explicitly indicated.**
+For example, "<kbd>Y</kbd>, <kbd>Y</kbd>" means pressing lowercase <kbd>y</kbd> twice, while "<kbd>Shift-Y</kbd>, <kbd>Y</kbd>" means pressing <kbd>Shift</kbd>+<kbd>y</kbd> followed by a lowercase <kbd>y</kbd>.
 
-Shortcuts this extension introduces:
+Shortcuts that this extension introduces:
 
 ### Vim Ex commands
 
 | Command  | Action                     |
 | -------- | -------------------------- |
 | :w[rite] | Save Notebook              |
-| :q[uit]  | Enter Jupyter command mode |
-
-### Vim command bindings
-
-| Chord           | Action                    |
-| --------------- | ------------------------- |
-| Ctrl-O, U       | Undo Cell Action          |
-| -               | Split Cell at Cursor      |
-| Ctrl-O, -       | Split Cell at Cursor      |
-| Ctrl-O, D       | Cut Cell                  |
-| Ctrl-O, Y       | Copy Cell                 |
-| Ctrl-O, P       | Paste Cell                |
-| Ctrl-Shift-J    | Extend Marked Cells Below |
-| Ctrl-Shift-K    | Extend Marked Cells Above |
-| Ctrl-O, O       | Insert Cell Below         |
-| Ctrl-O, Ctrl-O  | Insert Cell Above         |
-| Ctrl-J          | Select Cell Below         |
-| Ctrl-K          | Select Cell Above         |
-| Ctrl-O, G       | Select First Cell         |
-| Ctrl-O, Ctrl-G  | Select Last Cell          |
-| Ctrl-E          | Move Cell Down            |
-| Ctrl-Y          | Move Cell Up              |
-| Ctrl-O, Z, Z    | Center Cell               |
-| Ctrl-G          | Show Tooltip              |
-| Command/Ctrl-1  | Code Cell Mode            |
-| Command/Ctrl-2  | Markdown Cell Mode        |
-| Command/Ctrl-3  | Raw Cell Mode             |
-| Shift-Escape    | Leave Vim Mode            |
-| Escape, Ctrl-\[ | Exit Vim Insert Mode      |
-
-### Jupyter command bindings
-
-| Chord   | Action              |
-| ------- | ------------------- |
-| G, G    | Select First Cell   |
-| Shift-G | Select Last Cell    |
-| D, D    | Delete Cell         |
-| Y, Y    | Yank (Copy) Cell    |
-| P       | Paste Cell          |
-| Shift-P | Paste Cell Above    |
-| O       | Insert Cell         |
-| Shift-O | Insert Cell Above   |
-| U       | Undo Cell Action    |
-| Ctrl-E  | Move Cells Down     |
-| Ctrl-Y  | Move Cells Up       |
-| Z, Z    | Center Cell         |
-| Z, C    | Hide Code Cell      |
-| Z, O    | Show Code Cell      |
-| Z, M    | Hide All Code Cells |
-| Z, R    | Show All Code Cells |
+| :q[uit]  | Enter Jupyter Command Mode |
+
+### Vim (Jupyter Edit mode) bindings
+
+| Shortcut       | Action                    |
+| -------------- | ------------------------- |
+| -              | Split Cell at Cursor      |
+| Ctrl-O, -      | Split Cell at Cursor      |
+| Ctrl-Shift-J   | Extend Marked Cells Below |
+| Ctrl-Shift-K   | Extend Marked Cells Above |
+| Ctrl-J         | Select Cell Below         |
+| Ctrl-K         | Select Cell Above         |
+| Ctrl-O, G      | Select First Cell         |
+| Ctrl-O, Ctrl-G | Select Last Cell          |
+| Ctrl-O, O      | Insert Cell Below         |
+| Ctrl-O, Ctrl-O | Insert Cell Above         |
+| Ctrl-O, D      | Delete (Cut) Cell         |
+| Ctrl-O, Y      | Yank (Copy) Cell          |
+| Ctrl-O, P      | Paste Cell Below          |
+| Ctrl-E         | Move Cell Down            |
+| Ctrl-Y         | Move Cell Up              |
+| Ctrl-O, U      | Undo Cell Action          |
+| Ctrl-O, Z, Z   | Center Cell               |
+| Ctrl-G         | Show Tooltip              |
+| Cmd/Ctrl-1     | Change to Code Cell       |
+| Cmd/Ctrl-2     | Change to Markdown Cell   |
+| Cmd/Ctrl-3     | Change to Raw Cell        |
+| Shift-Esc      | Exit to Command Mode      |
+| Esc or Ctrl-\[ | Exit Current Mode         |
+
+### Jupyter Command mode bindings
+
+| Shortcut | Action              |
+| -------- | ------------------- |
+| G, G     | Select First Cell   |
+| Shift-G  | Select Last Cell    |
+| O        | Insert Cell Below   |
+| Shift-O  | Insert Cell Above   |
+| D, D     | Delete (Cut) Cell   |
+| Y, Y     | Yank (Copy) Cell    |
+| P        | Paste Cell Below    |
+| Shift-P  | Paste Cell Above    |
+| Ctrl-E   | Move Cells Down     |
+| Ctrl-Y   | Move Cells Up       |
+| U        | Undo Cell Action    |
+| Z, Z     | Center Cell         |
+| Z, C     | Hide Code Cell      |
+| Z, O     | Show Code Cell      |
+| Z, M     | Hide All Code Cells |
+| Z, R     | Show All Code Cells |
 
 ### Switching between modes
 
@@ -114,11 +114,11 @@ Shortcuts this extension introduces:
   - To leave Normal mode to Command mode, several options are available:
     - <kbd>Shift</kbd>+<kbd>Esc</kbd>
     - <kbd>Esc</kbd> or <kbd>Ctrl</kbd>+<kbd>[</kbd>, if the "Enable `Esc` and `Ctrl-[` leaving vim Normal mode to Jupyter Command mode" option is enabled (on by default). To disable the option, go to Settings menu → Settings Editor → Notebook Vim.
-  - To enter Insert mode from Normal mode, use one of the insert commmands, such as <kbd>i</kbd>, <kbd>I</kbd>, <kbd>a</kbd>, <kbd>A</kbd>, <kbd>o</kbd>, <kbd>O</kbd>, <kbd>c</kbd>, <kbd>C</kbd>, <kbd>s</kbd> or <kbd>S</kbd>.
-  - To enter Visual Mode from Normal mode, use one of the visual commands, such as <kbd>v</kbd>, <kbd>V</kbd> or <kbd>Ctrl</kbd>+<kbd>V</kbd>.
-- From Insert or Visual modes:
-  - To leave Insert or Visual modes to Normal Mode, press <kbd>Esc</kbd> or <kbd>Ctrl</kbd>+<kbd>[</kbd>.
-  - To leave Insert or Visual modes to Command Mode, press <kbd>Shift</kbd>+<kbd>Esc</kbd>.
+  - To enter Insert mode from Normal mode, use one of the insert commmands, such as <kbd>i</kbd>, <kbd>Shift</kbd>+<kbd>i</kbd>, <kbd>a</kbd>, <kbd>Shift</kbd>+<kbd>a</kbd>, <kbd>o</kbd>, <kbd>Shift</kbd>+<kbd>o</kbd>, <kbd>c</kbd>, <kbd>Shift</kbd>+<kbd>c</kbd>, <kbd>s</kbd> or <kbd>Shift</kbd>+<kbd>s</kbd>.
+  - To enter Visual mode from Normal mode, use one of the visual commands, such as <kbd>v</kbd>, <kbd>Shift</kbd>+<kbd>v</kbd> or <kbd>Ctrl</kbd>+<kbd>v</kbd>.
+- From Insert or Visual mode:
+  - To leave Insert or Visual mode to Normal mode, press <kbd>Esc</kbd> or <kbd>Ctrl</kbd>+<kbd>[</kbd>.
+  - To leave Insert or Visual mode to Command mode, press <kbd>Shift</kbd>+<kbd>Esc</kbd>.
 
 ## Special Thanks