Problem: can't view problems by context
I want to be able to view problems based on what context they are applicable to.
For example, I want to see which problems are related to the Engine repository, but not spaceman. If I could tag problems with the relevant repository and filter by this, that would be great.
Some other things I might want to filter by are langauge, difficulty level, etc.
Solution:
Implement a state machine that administers tags.
Tags should have types, e.g. `language`, `repository`, `difficulty`.