Merge pull request #336 from github/pr-template

Update link in PR template

Author: henrymercer

.github/pull_request_template.md

@@ -7,6 +7,6 @@ Replace this with a description of the changes your pull request makes.
 
 ## Checklist
 
-- [ ] [CHANGELOG.md](../extensions/ql-vscode/CHANGELOG.md) has been updated to incorporate all user visible changes made by this pull request.
+- [ ] [CHANGELOG.md](https://github.com/github/vscode-codeql/blob/master/extensions/ql-vscode/CHANGELOG.md) has been updated to incorporate all user visible changes made by this pull request.
 - [ ] Issues have been created for any UI or other user-facing changes made by this pull request.
 - [ ] `@github/product-docs-dsp` has been cc'd in all issues for UI or other user-facing changes made by this pull request.