[libadwaita] (16 commits) ...demo: Use a new window button instead of menu for tab view

[Alexander Mikhaylenko <alexm src gnome org>]

Summary of changes:

  5b6f744... version: Add runtime version functions (*)
  9eb6a09... examples: Make the demo non-unique (*)
  0045aba... examples: Adwaita.Demo -> Adwaita1.Demo (*)
  da7bc9a... Rename examples/ to demo/ (*)
  b6a1f45... demo: Add icons, appdata and desktop file (*)
  cab4fe2... demo: Add a mnemonic for Preferences in primary menu (*)
  c6b686e... demo: Add an about dialog (*)
  b6fafc0... demo: Use a better welcome icon (*)
  69daa02... demo: Expose desktop file in flatpak (*)
  e324ba4... ci: Publish demo nightlies (*)
  b462ee3... demo: Add inspector to the primary menu (*)
  c48ff1f... demo: Use AdwPreferencesGroup where possible (*)
  804082f... demo: Polish lists page (*)
  9c724e0... demo: Expand the leaflet subpage contents (*)
  07b0ded... preferences-window: Remove the welcome label (*)
  a46d9a7... demo: Use a new window button instead of menu for tab view (*)

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