fix: update check_pr_size usage example with --repo and --pr-number args

Implements: REQ-1

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

src/devx/ci/check_pr_size.py

@@ -9,7 +9,8 @@ PRs with the ``refactoring`` label bypass the size check — large but
 legitimate refactoring PRs that touch many files in a coordinated way.
 
 Usage:
-    python -m devx.ci.check_pr_size --base origin/master --head HEAD
+    python -m devx.ci.check_pr_size --base origin/master --head HEAD \\
+        --repo oblachno-oss/grm --pr-number 123
 
 In CI, pass ``--github-output`` to set ``pr-size-ok`` and ``pr-size-detail``
 for downstream steps.