Update contributing guidelines to say not to open new issues for algorithms (TheAlgorithms#9760)

* updated CONTRIBUTING.md with markdown anchors and issues

* removed testing header from previous PR

Author: ChrisO345

Diff for: CONTRIBUTING.md

@@ -25,8 +25,12 @@ We appreciate any contribution, from fixing a grammar mistake in a comment to im
 
 Your contribution will be tested by our [automated testing on GitHub Actions](https://github.com/TheAlgorithms/Python/actions) to save time and mental energy.  After you have submitted your pull request, you should see the GitHub Actions tests start to run at the bottom of your submission page.  If those tests fail, then click on the ___details___ button try to read through the GitHub Actions output to understand the failure.  If you do not understand, please leave a comment on your submission page and a community member will try to help.
 
+#### Issues
+
 If you are interested in resolving an [open issue](https://github.com/TheAlgorithms/Python/issues), simply make a pull request with your proposed fix. __We do not assign issues in this repo__ so please do not ask for permission to work on an issue.
 
+__Do not__ create an issue to contribute an algorithm. Please submit a pull request instead.
+
 Please help us keep our issue list small by adding `Fixes #{$ISSUE_NUMBER}` to the description of pull requests that resolve open issues.
 For example, if your pull request fixes issue #10, then please add the following to its description:
 ```