switch param best practice (Azure#14142)

Author: isra-fel

Diff for: documentation/development-docs/examples/switch-param-best-practice.md

@@ -0,0 +1,21 @@
+# Switch Parameter Best Practice
+
+## DO NOT use `IsParameterBound()` on a switch parameter
+
+```csharp
+// anti-pattern
+if (this.IsParameterBound(c => c.PassThru))
+{
+    WriteObject(true);
+}
+```
+
+It is possible to pass a `$false` to switch parameter, in that case, however, `IsParameterBound()` will still return `true`.
+
+## DO use `if (SwitchParamName)` to check a switch parameter
+
+```csharp
+if (PassThru)
+{
+    WriteObject(true);
+}