v0.31.3-ls119

LinuxServer Changes:

Make APP_URL var required (upstream changes).
bookstack Changes:

Links

• Update instructions

Full List of Changes

This release contains the following fixes and changes:

• Fixed issue where markdown strikethroughs were not rendering in the markdown editor. (#2470)
• Updated Turkish translations. (#2469)
• Updated some user, page and shelf views to use more efficient database querying.