Fix grammar/wording/etc. in Appdata files section

docs/freedesktop-quick-reference.rst

@@ -60,13 +60,13 @@ interested, you can read also the full spec
 Appdata files
 -------------
 
-Appdata files are used by application stores (eg. kde discover, gnome
-software) in order to display metadata about your application, such as a
-description, screenshots, display changelogs on update, among other
-things.
+Appdata files are used by application stores (e.g. KDE Discover, GNOME
+Software) in order to display metadata about your application, such as a
+description, screenshots, changelogs when updates are available, and
+other miscellaneous things.
 
-your desktop file should be prefixed with your application's appid and
-placed in ``/app/share/metainfo/``, you should also use
+Your Appdata file should be prefixed with your application's appid and
+placed in ``/app/share/metainfo/``. You should also use
 ``appstream-util validate-relax`` to check your file for errors before
 including it.
 
@@ -77,4 +77,4 @@ Example:
     /app/share/metainfo/org.gnome.Dictionary.appdata.xml
 
 If interested, you can read the full spec
-`here <https://www.freedesktop.org/software/appstream/docs/>`__
+`here <https://www.freedesktop.org/software/appstream/docs/>`__.