increase version to 20.0.0 (see note below)

With start of Kodi 20 Nexus, takes addon as major the same version number as Kodi.
This done to know easier to which Kodi the addon works.

For here now used by Kodi 20 Nexus.

Author: AlwinEsch

pvr.stalker/addon.xml.in

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <addon
   id="pvr.stalker"
-  version="7.1.1"
+  version="20.0.0"
   name="Stalker Client"
   provider-name="Jamal Edey">
   <requires>@ADDON_DEPENDS@</requires>

pvr.stalker/changelog.txt

@@ -1,3 +1,13 @@
+v20.0.0
+- Translations updates from Weblate
+  - Danish (da_dk)
+  - To allow also addon.xml content update by Weblate
+- Minor cleanups on addon.xml
+- Changed test builds to 'Kodi 20 Nexus'
+- Increased version to 20.0.0
+  - With start of Kodi 20 Nexus, takes addon as major the same version number as Kodi.
+    This done to know easier to which Kodi the addon works.
+
 v7.1.1
 - Language update from Weblate