Update PULL_REQUEST_TEMPLATE.md

Author: unixorn

PULL_REQUEST_TEMPLATE.md

@@ -9,7 +9,7 @@
 <!--- What types of changes does your submission introduce? Put an `x` in all the boxes that apply: -->
 
 - [ ] A helper script
-- [ ] A link to an external resource like a blog post
+- [ ] A link to an external resource like a blog post or video
 
 # Checklist:
 
@@ -20,5 +20,6 @@
 - [ ] Any scripts added use `#!/usr/bin/env interpreter` instead of potentially platform-specific direct paths (`#!/bin/sh` is an ok exception)\
 - [ ] Scripts are marked executable
 - [ ] I have added a credit line to README.md for the script
+- [ ] If there was no author credit in a script added in this PR, I have added one.
 - [ ] I have confirmed that the link(s) in my PR are valid.
 - [ ] I have read the **CONTRIBUTING** document.