Fix missing comma in FAQ.md (#3134)

diff --git a/docs/FAQ.md b/docs/FAQ.md
index 3d73a0f..6c14076 100644
--- a/docs/FAQ.md
+++ b/docs/FAQ.md
@@ -168,7 +168,7 @@
 - Unique ID are often derived from a string label and at minimum scoped within their host window:
 ```c
 Begin("MyWindow");
-Button("OK");          // Label = "OK",     ID = hash of ("MyWindow" "OK")
+Button("OK");          // Label = "OK",     ID = hash of ("MyWindow", "OK")
 Button("Cancel");      // Label = "Cancel", ID = hash of ("MyWindow", "Cancel")
 End();
 ```