Reformat all markdown

[J4bbi]

This PR implements a Markdown style guide

• wraps lines at 120 chars
• adds a format type descriptor for all code quotes (i.e. json, bash, xml)
• fixes typos
• fixes grammatical errors

For more information:

• https://google.github.io/styleguide/docguide/style.html
• https://docs.gruntwork.io/guides/style/markdown-style-guide/
• https://about.gitlab.com/handbook/markdown-guide/

[github-actions[bot]]

Hi @J4bbi, Conflicts have been detected against the base branch. Please resolve these conflicts as soon as you can. Thanks!