Update PR template to prompt thinking on change log entry (#968)

* Add section on changelog updates to PR template

Signed-off-by: Daniel Carl Jones <djonesoa@amazon.com>

* Add links to changelogs

Signed-off-by: Daniel Carl Jones <djonesoa@amazon.com>

---------

Signed-off-by: Daniel Carl Jones <djonesoa@amazon.com>

.github/pull_request_template.md

@@ -8,6 +8,19 @@ Relevant issues: <!-- Please add issue numbers. -->
 
 <!-- Please confirm there's no breaking change, or call our any behavior changes you think are necessary. -->
 
+## Does this change need a changelog entry in any of the crates?
+
+<!--
+    Please confirm yes or no.
+    If no, add justification. If unsure, ask a reviewer.
+
+    You can find the changelog for each crate here:
+    - https://github.com/awslabs/mountpoint-s3/blob/main/mountpoint-s3/CHANGELOG.md
+    - https://github.com/awslabs/mountpoint-s3/blob/main/mountpoint-s3-client/CHANGELOG.md
+    - https://github.com/awslabs/mountpoint-s3/blob/main/mountpoint-s3-crt/CHANGELOG.md
+    - https://github.com/awslabs/mountpoint-s3/blob/main/mountpoint-s3-crt-sys/CHANGELOG.md
+-->
+
 ---
 
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