remove submodule section of PR template

.github/PULL_REQUEST_TEMPLATE.md

@@ -8,22 +8,5 @@ _Hint_: Use the phrase '_This resolves #< issue number >_' so that they are link
 
 ## Check List
 - [ ] I successfully compiled _ldmx-sw_ with my developments
-- [ ] I ran my developments and the following shows that they are successful. <!-- put plots or some other proof that your developments work and do the intended function -->
-- [ ] I attached any sub-module related changes to this PR.
-<!--
-EXPLANATION: You need to specifically `git add` your submodule's commit in ldmx-sw and then have a separate PR within that submodule.
-
-  # outline of submodule commit updating
-  cd SUBMODULE
-  git checkout updates
-  cd ..
-  git add SUBMODULE
-  git commit -m "I updated the commit for SUBMODULE to the last commit of my-updates"
--->
-
-### Related Sub-Module PRs
-<!--
-If you have developments in a submodule that you need to merge in along with these developments, please link those PRs here, otherwise just delete this section.
-NOTE: You do not need to make a Sub-Module PR if your submodule developments are already on that repo's default branch.
--->
-- 
+- [ ] I ran my developments and the following shows that they are successful.
+<!-- put plots or some other proof that your developments work and do the intended function -->