Highlighting Doc: expand explanation about XML files directory

doc/katepart/development.docbook

@@ -229,20 +229,27 @@ Highlighting repository</ulink> in the file <filename>language.xsd</filename>
 
 <para>Custom <filename class="extension">.xml</filename> highlight definition files are
 located in <filename class="directory">org.kde.syntax-highlighting/syntax/</filename> in
-your user folder found with <userinput><command>qtpaths</command><option>--paths
-GenericDataLocation</option></userinput> which usually is
-<filename class="directory"><envar>$HOME</envar>/.local/share/</filename>.
-</para>
-
-<para>On &Windows; these files are located <filename>%USERPROFILE%/AppData/Local/org.kde.syntax-highlighting/syntax</filename>.
-<replaceable>%USERPROFILE%</replaceable> usually expands to <filename>C:\\Users\\<replaceable>user</replaceable></filename>.</para>
-
-<para>For <ulink url="https://flathub.org/apps/details/org.kde.kate">Kate's Flatpak package</ulink>,
-these files are located <filename class="directory"><envar>$HOME</envar>/.var/app/org.kde.kate/data/org.kde.syntax-highlighting/syntax/</filename>
+your user folder found with <userinput><command>qtpaths</command><option> --paths
+GenericDataLocation</option></userinput> which usually are
+<filename class="directory"><envar>$HOME</envar>/.local/share/</filename>
+and <filename class="directory">/usr/share/</filename>.
+</para>
+
+<para>For Flatpak and Snap packages, the data location is different
+for each application. In a Flatpak application, usually is
+<filename class="directory"><envar>$HOME</envar>/.var/app/<replaceable>package-name</replaceable>/data/</filename>
+and in a Snap application is
+<filename class="directory"><envar>$HOME</envar>/snap/<replaceable>package-name</replaceable>/current/.local/share/</filename>.
+For example, for <ulink url="https://flathub.org/apps/details/org.kde.kate">Kate's Flatpak package</ulink>,
+the custom &XML; files are located in
+<filename class="directory"><envar>$HOME</envar>/.var/app/org.kde.kate/data/org.kde.syntax-highlighting/syntax/</filename>
 and for <ulink url="https://snapcraft.io/kate">Kate's Snap package</ulink>,
 it is <filename class="directory"><envar>$HOME</envar>/snap/kate/current/.local/share/org.kde.syntax-highlighting/syntax/</filename>.
 </para>
 
+<para>On &Windows; these files are located <filename>%USERPROFILE%&#92;AppData&#92;Local&#92;org.kde.syntax-highlighting&#92;syntax</filename>.
+<replaceable>%USERPROFILE%</replaceable> usually expands to <filename>C:&#92;Users&#92;<replaceable>user</replaceable></filename>.</para>
+
 <para>If multiple files exist for the same language, the file with the highest <userinput>version</userinput> attribute in the <userinput>language</userinput> element will be loaded.</para>
 
 <variablelist>