Update PULL_REQUEST_TEMPLATE.md (#1067)

* Update PULL_REQUEST_TEMPLATE.md

Updated the PR template to put a reminder, so that when we do new version releases we notify the comms team about it in advance.

Signed-off-by: Adi Seredinschi <adi@informal.systems>

* using releases.md instead of PR template

* Apply suggestions from code review

Co-authored-by: Rano | Ranadeep <ranadeep@informal.systems>
Signed-off-by: Farhad Shabani <Farhad.Shabani@gmail.com>

---------

Signed-off-by: Adi Seredinschi <adi@informal.systems>
Signed-off-by: Farhad Shabani <Farhad.Shabani@gmail.com>
Co-authored-by: Farhad Shabani <Farhad.Shabani@gmail.com>
Co-authored-by: Rano | Ranadeep <ranadeep@informal.systems>

RELEASES.md

@@ -48,6 +48,11 @@ Our release process is as follows:
     then update the release description and append:
    `[📖CHANGELOG](https://github.com/cosmos/ibc-rs/blob/main/CHANGELOG.md#vXYZ)`
 
+### Communications (non-technical) release pipeline
+
+- Notify the communications team about the pending release and prepare an announcement.
+- Coordinate with other organizations that are active in IBC development (e.g., Interchain) and keep them in the loop.
+
 All done! 🎉
 
 [crates.io]: https://crates.io