db: add category and description indexes on mod_actions table.

db/migrate/20220919041622_add_indexes_to_mod_actions.rb

@@ -0,0 +1,7 @@
+class AddIndexesToModActions < ActiveRecord::Migration[7.0]
+  def change
+    add_index :mod_actions, :category
+    add_index :mod_actions, :description, using: :gin, opclass: :gin_trgm_ops
+    add_index :mod_actions, "to_tsvector('pg_catalog.english', description)", using: :gin
+  end
+end