Copy-paste **Online accounts to join** section from GDOCs

[marcobarilari]

GDocs link

• [x] copy paste (no big content edit for now) the text from gdoc to online_accounts_to_join.md file (the file is here
• [x] edit the text on GitHub to markdown rules (basic cheatsheet here)
  • [x] if there are links report them in markdown style
  • [x] If there are "confidential information" take note and discuss with others how to tackle them, discussion can happen in the comment section of the PR
• [x] If you see that a section might need some edits (old/wrong info, missing parts, etc), please open an issue pointing to that
• [x] When done, ask @marcobarilari and @fcerpe to review your edits on the PR
• [x] Highlight in red the section you just worked on on the gdoc
• [x] Enjoy the review process

Here are the slides we discussed at the LM

If something is not clear, do not hesitate to contact @marcobarilari or @fcerpe for help.

If you do not have time to do it please let us know by commenting on this issue.

Thanks