feat: demo patches

* disclaimer at top
 * build script
 * umami for usage data

docs: update README

fix: fix cookie issue

fix: verify users existence in IsAuthenticated

fix: better example compose

feat: oidc option for issuer trailing slash

fix: update tag check in ci again

feat: maybe possibly only build on tags?

docs: update example docker-compose

feat: first ci attempt

feat: show version number in settings

docs: update todos in readme

feat: tixe-input css class

feat: error.tmpl

fix: abort if not logged in...

feat: link management!

fix: comments in TagsDelete

docs: relicense to AGPL 3.0, update name to lowercase

docs: remove old comment

fix: make placeholder lighter in tag input