Migrate relevant documentation to repository from docs repository.

[maxachis]

Fixes

• #13 of docs repository: migrate dev docs to in-repo markdown

Description

• Create docs folder
• Move api_docs folder from docs repository
• Move data-dictionaries from docs repository
• Except for record-types-taxonomy, which has been moved into terminology.md of docs repository

Testing

• Evaluate that documentation moved from this directory is as expected and conforming to Host web server for front end on Digital Ocean #13

Performance

• Documentation, so minimal performance impact.

Docs

• lol