Update CONTRIBUTING.md (#1524)

updated the link to "Ways to contribute"

removed the link to https://help.nextcloud.com/t/testing-nextcloudpi/126380 for now (as this one is still in draft-status + needs to be rewritten)


Signed-off-by: Jürgen <55851807+schoetju@users.noreply.github.com>

CONTRIBUTING.md

@@ -2,8 +2,5 @@
 
 Check this wiki article if you want to learn how you can help.
 
-[Ways to contribute](https://docs.nextcloudpi.com/en/contribute/)
+[Ways to contribute](https://help.nextcloud.com/t/contribute-to-nextcloudpi/126384)
 
-Check this other article to learn about the process of contributing with code and with testing.
-
-[NCP Feature Workflow](https://docs.nextcloudpi.com/en/workflow-and-testing-of-new-features/)