docs: add example if statement in advanced-usage.md

lrq3000 · lrq3000 · commit 65bdb26ab91c · 2023-04-12T00:41:30.000+02:00
Signed-off-by: Stephen L. &lt;lrq3000@gmail.com&gt;
diff --git a/docs/advanced-usage.md b/docs/advanced-usage.md
@@ -234,6 +234,7 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
       - name: Display Python version
+        if: ${{ python-version != 'pypy2.7' }} # in if statements, use single-quotes (not double-quotes) in expressions to test input `python-version`
         run: python --version
 ```
 
