Add more type of change to the PR template (#924)

add more options for PR template
Signed-off-by: Phuong Nguyen <phuonguyen@nvidia.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -10,6 +10,8 @@ Fixes # (issue)
 - [ ] Bug fix (non-breaking change which fixes an issue)
 - [ ] New feature (non-breaking change which adds functionality)
 - [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
+- [ ] Infra/Build change
+- [ ] Code refractor
 
 ## Changes