fix(docs): removed double-link which broke the markdown formatting in…

… pr template (#532)

As is visible in the `Checklist before merging` section of #531, the
markdown link formatting was broken by a second link where only one
belonged.

Due to the shortness of the CONTRIBUTING.md document, I preferred the
link to the doc as a whole over the one which directed to the PR
requirements header.

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [X] Other (security config, docs update, etc)

## Checklist before merging

- [X] Test, docs, adr added or updated as needed
- [X] [Contributor Guide
Steps](https://github.com/defenseunicorns/uds-template-capability/blob/main/CONTRIBUTING.md)(https://github.com/defenseunicorns/uds-template-capability/blob/main/CONTRIBUTING.md#submitting-a-pull-request)
followed

.github/pull_request_template.md

@@ -17,4 +17,4 @@ Relates to #
 ## Checklist before merging
 
 - [ ] Test, docs, adr added or updated as needed
-- [ ] [Contributor Guide Steps](https://github.com/defenseunicorns/uds-template-capability/blob/main/CONTRIBUTING.md)(https://github.com/defenseunicorns/uds-template-capability/blob/main/CONTRIBUTING.md#submitting-a-pull-request) followed
+- [ ] [Contributor Guide](https://github.com/defenseunicorns/uds-template-capability/blob/main/CONTRIBUTING.md) followed