add a real examplefile instead of an .gitignore which is a bit stupid here

core/skeleton/.gitignore

@@ -1,4 +0,0 @@
-# Ignore everything in this directory
-*
-# Except this file
-!.gitignore

core/skeleton/welcome.txt

@@ -0,0 +1,5 @@
+Welcome to your ownCloud account!
+
+This is just an example file for developers and git users. 
+The packaged and released versions will come with better examples.
+