Merge pull request ppy#2253 from nanaya/hide_deleted_empty_beatmaps

Hide deleted beatmaps with no discussions

Merge pull request ppy#2075 from notbakaneko/feature/index-via-readonly

Use read-only connection for indexing query instead of primary

Merge pull request ppy#2066 from nanaya/fix_users_show

Limit parsing params to relevant actions

Merge pull request ppy#2026 from nanaya/wiki_search

Index wiki page title