Swap full stop for comma (#855)

:)

Author: lawrence0arabia

src/content/docs/tutorials/counter-app/basic-app.md

@@ -47,7 +47,7 @@ welcome to use explicit imports if that is your preferred style.
 :::caution
 
 Some editors remove unused imports automatically, so if you run into errors about missing types,
-etc. make sure these are in place. and double-check that shared imports like `Stylize` come from
+etc. make sure these are in place, and double-check that shared imports like `Stylize` come from
 ratatui and not crossterm to avoid conflicts.
 
 :::