* Fix crowdin badge display in CONTRIBUTING.md
The Crowdin localization badge in `CONTRIBUTING.md` appeared to have the wrong markup around it. This manifested in some extra brackets and an unformatted `crowdin` string.
* Make Crowdin badge a link to the Mastodon project
Conflicts:
- .github/ISSUE_TEMPLATE/bug_report.md
Took our version.
- CONTRIBUTING.md
Updated the embedded copy of upstream's version.
- README.md
Took our version.
- app/policies/status_policy.rb
Not a real conflict, took code from both.
- app/views/layouts/embedded.html.haml
Added upstream's changes (dns-prefetch) and fixed
`%body.embed`
- app/views/settings/preferences/show.html.haml
Reverted some of upstream changes, as we have a
page dedicated for flavours and skins.
- config/initializers/content_security_policy.rb
Kept our version of the CSP.
- config/initializers/doorkeeper.rb
Not a real conflict, took code from both.
* Remove docker guide and put it in docs repo
* Move tasks to docs repo
* Move requirements to contributing doc
* Move advice about tagged releases to docs repo
* Move local domain and host config to docs repo
* Link to related tech
Thibaut Girka