Docs - Revise CONTRIBUTING.md

- Change URL from "bugs" to "support" for the "ticket" system.
- NEWS has been removed in favor of "Changelog: " trailers.
- Strongly prefer `git format-patch` submissions.
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 28296d5..5305932 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,12 +1,12 @@
-NOTES FOR GITHUB DEVELOPERS
----------------------------
+NOTES FOR DEVELOPERS
+--------------------
 
 The official issue tracker for Slurm is at
-  https://bugs.schedmd.com/
+  https://support.schedmd.com/
 
 We welcome code contributions and patches, but **we do not accept Pull Requests
 through GitHub at this time.** Please submit patches as attachments to new
-bugs under the "C - Contributions" severity level.
+tickets under the "C - Contributions" severity level.
 
 TARGET RELEASES
 ---------------
@@ -54,7 +54,8 @@
 
 PATCH SUBMISSION
 ----------------
-An entry in `NEWS` should describe the change or new functionality.
+A "Changelog: " trailer in the commit message should describe the change or
+new functionality.
 
 Please break patches up into logically separate chunks, while ensuring that
 each patch can still be compiled. (Anticipate that a developer using `git
@@ -69,8 +70,7 @@
 spelling mistake), please send the command/regex used to generate the changes
 along with the patch, or note it in the commit message.
 
-While not required, we encourage use of `git format-patch` to generate the
-patch. This ensures the relevant author line and commit message stay attached.
-Plain `diff`'d output is also okay. In either case, please attach them to the
-bug for us to review. Spelling corrections or documentation improvements can be
-suggested without attaching the patch as long as you describe their location.
+We strongly encourage the use of `git format-patch` to generate the patch. This
+ensures the relevant author line and commit message stay attached. Spelling
+corrections or documentation improvements can be suggested without attaching
+the patch as long as you describe their location.