Documentation changes to .md files

[AsherAtTrent]

Changes I made and why

Added changes to markdown files to be more consistent with each other in terms of formatting. I followed the linting rules of markdownlint, a popular VS code plugin, and the formatting of Keep a Changelog to make these changes.

Majority of these changes had no visual impact on the rendered markdown, however they arguably improved code readability while also adding consistency to how they were written inside markdown.

Changes with visual impact:

• added a shell language tag to a code fence in README.md to give small highlighting
• removed semicolons in CHANGELOG.md that were inconsistently placed (i.e. Update: and Update)
• changed every markdown file to have a top-level heading where applicable

Other possible changes to build on

CHANGELOG.md does not exactly follow Keep a Changelog, as its missing the "unreleased" section at the top as well as links on every version number showing the GitHub diff comparison between that version and the previous. This could also be done in the future if possible/appropriate.

Side Note

This is my first time making a contribution to a repository outside of academia and personal projects. Sorry in advance if I did anything incorrectly and please let me know what I should/could have done!

[jdneo]

Hi @AsherAtTrent,

Thank you for contribution. I'm ok for making changes to readme and changelog. Please not change the security.md because it's generated automatically from our org. If its content needs to be updated, some bots should help to do that I think.