add blurb about PR title format and make focus area optional

Author: sleepyStick

.github/pull_request_template.md

@@ -1,4 +1,10 @@
 <!-- Thanks for contributing! -->
+<!-- Please ensure that the title of the PR is in the following form:
+[Issue Type]-[Issue Key]: Issue Title
+
+If you are an external contributor and there is no JIRA ticket associated with your change, then use your best judgement
+for the PR title. A MongoDB employee will create a JIRA ticket and edit the name and links as appropriate.
+-->
 [Issue Key](https://jira.mongodb.org/browse/%7BISSUE_KEY%7D)
 ## Summary
 <!-- What conceptually is this PR introducing? If context is already provided from the JIRA ticket, still place it in the
@@ -28,7 +34,7 @@ All code should be tested in some way – so please list what your validation st
 - [ ] Have you checked for spelling & grammar errors?
 - [ ] Is all relevant documentation (README or docstring) updated?
 
-## Focus Areas for Reviewer
+## Focus Areas for Reviewer (optional)
 <!-- List any complex portion of code you believe needs additional scrutiny and explain why. -->
 
 <!-- See also: https://docs.google.com/document/d/1Z-z6BDIBJ9G4fn4MBb7Ql5A1NiSY6nsLfEE3KuU_Btw/edit?tab=t.exaie3tsb7gl#heading=h.asd8fqlsyzb6 -->