Create pull_request_template.md

.github/pull_request_template.md

+_Please delete the questions below, and type the answers in their place instead_
+
+**[for Generic PRs]**  
+Do you have a forum thread linked to this PR?  
+What will this PR bring to the project for everyone?  
+Why are these changes necessary?  
+How did you implement them?  
+
+**[for Bugfix PRs]**  
+Is this PR linked to an issue? If so please link it here, if not please create one first, then link it.  
+Is there a forum thread linked to this issue? If so please link it here.  
+How did you resolve this issue?  
+How can it be verified that the issue has actually been resolved?