Added terms and probability-distributions folders and file

[SaraVegaKeene]

Description

Issue Solved

Type of Change

• Adding a new entry Term for Existing Concept Entry

Checklist

• All writings are my own.
• My entry follows the Codecademy Docs style guide.
• My changes generate no new warnings.
• I have performed a self-review of my own writing and code.
• I have checked my entry and corrected any misspellings.
• I have made corresponding changes to the documentation if needed.
• I have confirmed my changes are not being pushed from my forked main branch.
• I have confirmed that I'm pushing from a new branch named after the changes I'm making.
• I have linked any issues that are relevant to this PR in the Issues Solved section.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ PragatiVerma18
❌ SaraVKeene
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[PragatiVerma18]

Hey @SaraVegaKeene, thanks for contributing to docs, please go through the comments and do the required changes. Let me know if you need any help or have any questions.

Also, please sign the CLA agreement or else we won't be able to merge this PR.

[PragatiVerma18]

Hey @SaraVegaKeene, this PR now looks good for a second review.

Please sign the CLA so that we can proceed with that and then merge the PR. Please note that the PR can not be merged without you signing the CLA.

[avdhoottt]

Hey @SaraVegaKeene, I left some comments. Please go through them and make the changes. Thank you!!

[avdhoottt]

Can you please add a 1-2 line description of the code here?