[carldaws]

Adds five gems to existing categories, one line each, alphabetical:

• happy_slugs → Rails Permalinks & Slugs — random human-readable slugs for ActiveRecord models
• activerecord-postgresql-branched → Active Record DB Adapters — adapter giving each git branch its own PostgreSQL schema
• rubocop-guardrails → Code Metrics — RuboCop plugin with Rails golden-path cops
• filepress → Content Management Systems — flat-file content for Rails apps
• niceties → Rails Extensions — small Ruby/Rails helpers

Transparency: all five are mine (same author). All are published on RubyGems with MIT licenses and test suites. bundle exec rspec passes locally (222 examples, 0 failures).