doc: Update GitHub documentation links

CONTRIBUTING.md

@@ -81,7 +81,7 @@ facilitates social contribution, easy testing and peer review.
 
 To contribute a patch, the workflow is as follows:
 
-  1. Fork repository ([only for the first time](https://help.github.com/en/articles/fork-a-repo))
+  1. Fork repository ([only for the first time](https://docs.github.com/en/get-started/quickstart/fork-a-repo))
   1. Create topic branch
   1. Commit patches
 
@@ -182,7 +182,7 @@ for more information on helping with translations.
 ### Work in Progress Changes and Requests for Comments
 
 If a pull request is not to be considered for merging (yet), please
-prefix the title with [WIP] or use [Tasks Lists](https://help.github.com/articles/basic-writing-and-formatting-syntax/#task-lists)
+prefix the title with [WIP] or use [Tasks Lists](https://docs.github.com/en/github/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#task-lists)
 in the body of the pull request to indicate tasks are pending.
 
 ### Address Feedback
@@ -386,7 +386,7 @@ about:
   - It may be because your code is too complex for all but a few people, and those people
     may not have realized your pull request even exists. A great way to find people who
     are qualified and care about the code you are touching is the
-    [Git Blame feature](https://help.github.com/articles/tracing-changes-in-a-file/). Simply
+    [Git Blame feature](https://docs.github.com/en/github/managing-files-in-a-repository/managing-files-on-github/tracking-changes-in-a-file). Simply
     look up who last modified the code you are changing and see if you can find
     them and give them a nudge. Don't be incessant about the nudging, though.
   - Finally, if all else fails, ask on IRC or elsewhere for someone to give your pull request