wine: Add Wine docs

Author: TheEvilSkeleton

docs/guides.rst

@@ -13,3 +13,4 @@ standard guidance provided elsewhere in the Flatpak documentation.
    electron
    qt
    multiarch
+   wine

docs/wine.rst

@@ -0,0 +1,16 @@
+Wine
+====
+
+Flathub contains an unofficial Wine stable BaseApp, stylized as `org.winehq.Wine <https://github.com/flathub/org.winehq.Wine>`__, to have and run Wine directly from within the Flatpak application. To use the Wine BaseApp, we need to explicitly specify it in the manifest and inherit all needed extensions:
+
+.. code-block:: yaml
+
+  base: org.winehq.Wine
+  base-version: stable-21.08 # Version of Wine BaseApp
+  inherit-extensions:
+    - org.freedesktop.Platform.GL32
+    - org.freedesktop.Platform.ffmpeg-full
+    - org.freedesktop.Platform.ffmpeg_full.i386
+    - org.winehq.Wine.gecko
+    - org.winehq.Wine.mono
+    - org.winehq.Wine.DLLs