Split out docs as a separate repo

[jakolehm]

Docs are now living in https://github.com/kontena/docs

[SpComb]

• The kontena repo 016030f710505189e6c73280bc7edcf6f9cd656d.. changes need to be merged into the new docs repo: Missing docs changes from kontena/kontena repo docs#1
• This PR will trigger merge conflicts for any open PRs that touch the docs: those need to be updated to split the docs changes out into a new PR against the docs repo
• Any open docs PRs will probably get closed: https://github.com/kontena/kontena/pulls?q=is%3Aopen+label%3Adocumentation+type%3Apr
• Open docs issues on the main github repo: documentation

[SpComb]

Linking to kontena/docs#1

What about all the open docs issues on the main repo? documentation

[jakolehm]

What about all the open docs issues on the main repo?

We need to migrate all relevant ones to the new repo and close others.

[SpComb]

Tracking all the backport PRs in kontena/docs#1

I'll merge this now to deal with the open docs PRs in this repo.