chore: update issue template (#154)

* chore: update issue template

* added to pr template

Author: paullatzelsperger

.github/ISSUE_TEMPLATE/feature_request.md

@@ -20,6 +20,10 @@ _e.g., DPF, CI, build, transfer, etc._
 
 _Are there any requirements?_
 
+## Who will sponsor this feature?
+
+_Please @-mention the committer that will sponsor your feature_.
+
 ## Solution Proposal
 
 _If possible, provide a (brief!) solution proposal._

.github/PULL_REQUEST_TEMPLATE.md

@@ -11,6 +11,12 @@ _Briefly state why the change was necessary._
 _List other areas of code that have changed but are not necessarily linked to the main feature. This could be method
 signature changes, package declarations, bugs that were encountered and were fixed inline, etc._
 
+
+## Who will sponsor this feature?
+
+_Please @-mention the committer that will sponsor your feature_.
+
+
 ## Linked Issue(s)
 
 Closes # <-- _insert Issue number if one exists_