Documentation repo: Migrate documentation to Ampersand repo

[basplijnaer]

Depends on

• Github Actions: Deploy docusaurus on pull request from Prototype #1325
• Github Actions: Deploy docusaurus on pull request from Ampersand repo #1316
• DocuGen repo: Setup initial Docusaurus website #1318

Problem Description
Docusaurus currently shows the hello world page from the ampersand repo. However it needs to show the actual documentation.

Tasks

• Notify the Ampersand team with the expected end date.
• Replace the contents of the "docs" folder in the Ampersand repo with the documentation from the documentation repo.
• Update the workflows to use the main branches instead of development

[basplijnaer]

The docs folder on the development branch of the Ampersand repo currently holds the contents of the documantation repo to make sure that all markdown files compile correctly. The applied changes can be found here.
The docs folder should be updated with the latest version of the GitBook documentation ones the Docusaurus website is taken into production.

• Update docs