Merge pull request #3928 from rtfd/humitos/template/issue

Mention RTD in the Project URL of the issue template

Author: RichardLitt

.github/ISSUE_TEMPLATE.md

@@ -1,8 +1,8 @@
 ## Details
 
-* Project URL: 
+* Read the Docs project URL:
 * Build URL (if applicable):
-* Read the Docs username (if applicable): 
+* Read the Docs username (if applicable):
 
 ## Expected Result