integration: add comment on slurp quotation marks

Author: johanmalm

src/integration.md

@@ -237,10 +237,13 @@ example
 - [swappy](https://github.com/jtheoof/swappy)
 
 ```
+grim -g "$(slurp)"
 grim -g "$(slurp)" - | swappy -f -
 grim - | wl-copy
 ```
 
+> Note: Remember to use quotation marks around `$(slurp)`
+
 # 7. Session Lock {#session-lock}
 
 `labwc` supports the [ext-session-lock] and [ext-idle-notify] protocols and you can use clients such