Add: EiC field to presubmission

This will allow us to track who leads which reviews and give credit to folks for their EiC efforts!

.github/ISSUE_TEMPLATE/presubmission-inquiry.md

@@ -10,7 +10,8 @@ assignees: ''
 Submitting Author: Name (@github_handle)  
 Package Name: 
 One-Line Description of Package: 
-Repository Link (if existing):   
+Repository Link (if existing):
+EiC: 
 
 ---