mkdocs deployment

[CBroz1]

This PR

• Removes all docs-parts, as they are now folded into md versions of the original rst docs proposed to be kept in in an archive directory as part of datajoint-docs PR 18
• Adds a doc contributor README with notes about vscode extensions that can aid in further contributions, including...
  • markdownlint for markdown linting
  • CSpell for spell checking
  • ReWrap for hard wrapping. While not necessary, this will help visualizing future git diffs.
• Migrates docs from docs.datajoint.org in a manner that mirrors the structure of datajoint-docs PR 18. While the central docs explain concepts, these submissions provide more concrete examples.
• Add CICD to deploy docs
• Adjust all examples to table definitions shown within the docs
• Final proof read pass
• Updated styling following DLC #63

Still needs

• Review/suggestions from @yambottle regarding CICD and turn on gh-pages

Note that not all the checks below will pass because I am issuing a PR to master rather than staging per advice of @guzman-raphael