Add a code review skill for AI

Added guidelines for code review process in SKILL.md.

@priya-sundaram-dev

Author: cclauss

.github/skills/code-review/SKILL.md

@@ -0,0 +1,13 @@
+Pull request-related rules in CONTRIBUTING.md should be observed in pull requests.
+
+Reviews should start with an `Is this an algorithm?` section that evaluates the PR for criteria in the `what-is-an-algorithm` section of CONTRIBUTING.md
+
+Compliance with the coding-style and other-requirements-for-submissions sections of CONTRIBUTING.md should also be verified.
+
+Does this pull request add, change, or delete multiple algorithms?
+
+Is this algorithm already in this repository?
+
+Is there another open pull request created earlier that is similar to this pull request?
+
+Was this algorithm plagiarized without giving proper credit?