update pr template

Update .github/release_template.md
Update .github/config.yml

Co-authored-by: Benedikt Kulmann <benedikt@kulmann.biz>

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

.github/pull_request_template.md

@@ -48,8 +48,7 @@ Please set the following labels:
 
 ## Checklist:
 <!-- Tick the checkboxes when done. -->
-<!-- Raise documentation ticket in opencloud.github.io/ -->
 - [ ] Code changes
 - [ ] Unit tests added
 - [ ] Acceptance tests added
-- [ ] Documentation ticket raised: <link> 
+- [ ] Documentation added