Add a security page

[njanssoone]

For users in companies where a security team manually validates allowed software lists, it would be a good idea to have a page explaining the different security-related elements, to help allowing Zed for the users.

Stuff that could be included (incomplete list):

• Where do community-related stuff live? On which servers (zed's? github's?)? Where are they hosted? (AWS?) Ex: users, calls, logs
• Do the multiplayer features and calls go through zed's server, or is it peer-to-peer? With which type of encryption, if any?
• Which filesystem / os rights does zed require to work in a minimal way? Which rights for all features?

I know some of these already exist in the current state of the docs, but grouping them all on a security-related page would definitely help adoption in heavily-regulated companies.

Thanks!