Update pull_request_template.md

Apply general writing codestyle for GitHub Pull Requests:

- move the "Closes #" text down to its own line, as GitHub prefers to read the git command without preceding text.
- move the text "(Does it build, tested in-game, etc.)" down to a new line to indicate where we want the info inserted.

pull_request_template.md

@@ -13,10 +13,14 @@
 - [ ] 3.3.5
 - [ ] master
 
-**Issues addressed:** Closes #  (insert issue tracker number)
+**Issues addressed:**
+
+Closes #  (insert issue tracker number)
 
 
-**Tests performed:** (Does it build, tested in-game, etc.)
+**Tests performed:**
+
+(Does it build, tested in-game, etc.)
 
 
 **Known issues and TODO list:** (add/remove lines as needed)