Add createGlobalStyle keyword

This commit adds support for the new keyword `createGlobalStyle` that
replaces `injectGlobal` in styled-components.

NOTE: The latter is kept as it's still part of the emotion API and also
      to be backwards compatible.

after/syntax/javascript.vim

@@ -149,7 +149,7 @@ syn match cssError contained "{@<>"
 
 " extend javascript matches to trigger styledDefinition highlighting
 syn match jsTaggedTemplate extend
-      \ "\<css\>\|\<keyframes\>\|\<injectGlobal\>\|\<fontFace\>"
+      \ "\<css\>\|\<keyframes\>\|\<injectGlobal\>\|\<fontFace\>\|\<createGlobalStyle\>"
       \ nextgroup=styledDefinition
 syn match jsFuncCall "\<styled\>\s*(.\+)" transparent
       \ nextgroup=styledDefinition

examples/apis.js

@@ -9,7 +9,7 @@ const genericTemplateString = `
  * Note: As glamor and emotion use similar APIs, only the extraneous APIs are
  *       mentioned later on.
  */
-import styled, { css, keyframes, injectGlobal } from 'styled-components';
+import styled, { css, keyframes, createGlobalStyle } from 'styled-components';
 
 // match of styled.method api
 // - unmatched cssTagName (note the double typoes and missing highlighting)
@@ -109,6 +109,17 @@ injectGlobal`
     margin: 0;
   }
 `;
+// - createGlobalStyle
+createGlobalStyle`
+  @font-face {
+    font-family: 'Operator Mono';
+    src: url('../fonts/Operator-Mono.ttf');
+  }
+
+  body {
+    margin: 0;
+  }
+`;
 
 // class based stylings
 class Container {