Update PR template to target staging branch

Author: JonDevOps

.github/PULL_REQUEST_TEMPLATE.md

@@ -5,7 +5,7 @@ edit this
 
 - [ ] I have read [w3Develops contribution guidelines](https://github.com/freeCodeCamp/freeCodeCamp/blob/master/CONTRIBUTING.md).
 - [ ] My pull request has a descriptive title (not a vague title like `Update index.md`)
-- [ ] My pull request targets the `production` branch of production.
+- [ ] My pull request targets the `staging` branch.
 - [ ] None of my changes are plagiarized from another source without proper attribution.
 - [ ] All the files I changed are in the same world language (for example: only English changes, or only Chinese changes, etc.)
 - [ ] My changes do not use shortened URLs or affiliate links.