Fix ServiceTypes, ExcludeServiceTypes, and DocPath desktop file entries to match XDG specifications

diff --git a/src/kvkbd.desktop b/src/kvkbd.desktop
index f6e742b..fb03a02 100644
--- a/src/kvkbd.desktop
+++ b/src/kvkbd.desktop
@@ -7,5 +7,5 @@
 Icon=kvkbd
 Type=Application
 Comment=A virtual keyboard for TDE
-DocPath=kvkbd/index.html
+X-DocPath=kvkbd/index.html
 Categories=Qt;TDE;Utility;X-TDE-Utilities-Peripherals;