Guides for infrequent operations

Topic
Migrating your OpenProject installation to PostgreSQL 13
Migrating your packaged OpenProject installation to another environment
Migrating your packaged OpenProject database to PostgreSQL
Migrating your Docker OpenProject database to PostgreSQL
[Migrating from an old MySQL database](./Migrating from an old MySQL database)
Fixing time entries corrupted by upgrading to 10.4.0
OpenProject Textile to Markdown migration
Custom OpenID Connect providers