Write documentation about goals, requirements and structure of the repository

[ESapenaVentura]

Description of the issue

As part of the checklist editor epic task ebi-ait/dcp-ingest-central#1, I would like to write/gather a brief but thorough documentation about the:

• [x] Overall goal of the repository (Should be around 1 paragraph long)
• [x] Requirements (Structure + content format)
• [x] Reproducibility
  • [x] Set goals about documentation thoroughness
  • [x] Set basic processes

[ESapenaVentura]

The document is here: https://docs.google.com/document/d/1IZaKUAWpQQ-mTaMjrTSiQfmfOquZCA7cE9i3GZ2Zqj4/edit

I think it's ready to start deployment of the repository!

[ESapenaVentura]

@Wkt8 to review document above (Thanks!)