[WIP] Data Platform - Documentation integration

[Y0Coss]

This Pull Rquest contains:

• The full Data Platform documentation.
• The related index edition compliant with the current 9-KB Help Center (not the upcoming 16 KB version).
• The Landing Page layout on all categories which contain actual content.

Edition of this content should be done via branches created from the YC-DP-integration-v2 and dedicated Pull Requests.

Do not merge this PR until I give a formal GO.