Add categories.yml and categories to features.yml competitors list
Closes #2431 (closed)
Add categories.yml and categories to features.yml competitors list. MVC so logic can get written and tested. Not all competitors in features.yml have categories assigned yet. In categories.yml, it is organized by "short name" of the categories and then there is "long_name" and "current" as sub-info. If "current" = no then GitLab currently doesn't have something that fills that category (although we are likely planning it) so it should not yet appear in the category list of competitors or have a competitor tagged with it.
These categories are largely from https://about.gitlab.com/handbook/product/categories and there are a lot of them, typically yielding more than one per competitor.
Further work is to continue tagging all competitors with categories.
We might also decide to merge CI and CD categories if we continue to not see them separately.