[gtk/matthiasc/for-master] (39 commits) ...docs: Move menu model docs

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  12adf63... Merge branch 'matthiasc/for-master' into 'master' (*)
  a837b57... popovermenu: Don't put a separator before the first section (*)
  473709f... popover: Allocate after setting final_position (*)
  b54ef5c... Merge branch 'menu-section-title-fixup' into 'master' (*)
  af32092... Merge branch 'popover-flip-arrow-fix' into 'master' (*)
  75c75e0... mediafile: Privately export function to the extension (*)
  5477c1c... inspector: Show the media backend (*)
  f66950f... Merge branch 'inspector-media' into 'master' (*)
  2a11f5f... Use attributes instead of element-type annotation (*)
  555230e... Annotate more functions returning GListModel (*)
  c6104fe... Drop parent->realized => child->realized invariant (*)
  064eb6a... Merge branch 'ebassi/for-master' into 'master' (*)
  65c56ea... Merge branch 'drop-realize-invariant' into 'master' (*)
  6784772... Updated Spanish translation (*)
  ccb890f... Use a slightly larger version of the logo animation (*)
  dc70815... video: Don't hide the controls while the popup is shown (*)
  3fee028... Merge branch 'widget-factory-larger-logo' into 'master' (*)
  b968ced... Reshuffle action muxer initialization (*)
  5ec53e6... Merge branch 'popup-controls-hiding' into 'master' (*)
  5f01f6f... Drop GtkStack:homogeneous (*)
  2e2121c... builder-tool: Replace GtkStack:homogeneous (*)
  c4a47e2... Speed up class action hookup (*)
  0a2e077... Merge branch 'drop-stack-homogeneous' into 'master' (*)
  b47e721... Merge branch 'class-action-init' into 'master' (*)
  91d8c23... popover: Fix repositioning logic (*)
  ac3d3c6... Merge branch 'popup-positioning-fix' into 'master' (*)
  6d9db86... build: clean up .pc generation (*)
  3209d0f... Merge branch 'wip/jtojnar/join-paths' into 'master' (*)
  55d2f19... docs: Update link to the discussion forum (*)
  f174158... docs: Link the contribution guide from the README (*)
  1b64a17... docs: Link the license file from the README (*)
  76cc1ca... Merge branch 'ebassi/for-master' into 'master' (*)
  f8ef15b... Add a quick sound test (*)
  4a44c1b... Merge branch 'soundcheck' into 'master' (*)
  662539a... CI: Switch to new Windows runners (*)
  02ac248... Update Ukrainian translation (*)
  062f0fe... Update Ukrainian translation (*)
  11351eb... Merge branch 'win32-new-runner' into 'master' (*)
  3bbcaa9... docs: Move menu model docs

(*) This commit already existed in another branch; no separate mail sent