docs: add mongo SLA link (#328)

Author: gssbzn

pull_request_template.md renamed to .github/pull_request_template.md

@@ -2,7 +2,7 @@
 
 Please include a summary of the fix/feature/change, including any relevant motivation and context.
 
-Link to any related issue(s): 
+Link to any related issue(s):
 
 ## Type of change:
 
@@ -14,8 +14,8 @@ Link to any related issue(s):
 
 ## Required Checklist:
 
-- [ ] I have signed the MongoDB CLA
-- [ ] I have read the Terraform contribution guidelines 
+- [ ] I have signed the [MongoDB CLA](https://www.mongodb.com/legal/contributor-agreement)
+- [ ] I have read the Terraform contribution guidelines
 - [ ] I have added tests that prove my fix is effective or that my feature works per HashiCorp requirments
 - [ ] I have added any necessary documentation (if appropriate)
 - [ ] I have run make fmt and formatted my code