docs(keycodes-symphony): Remove the "s" from displays

subjects/keycodes-symphony/README.md

@@ -6,7 +6,7 @@ Like an inspired Beethoven who's about to write his Moonlight Sonata, you're abo
 
 Write the function `compose`:
 - Make it fire every time a key is pressed.
-- Create a new `div` with the class `note` when a letter of the lowercase alphabet is pressed. It should have a unique background color generated using the `key` of the `event`. It should also displays the corresponding pressed character.
+- Create a new `div` with the class `note` when a letter of the lowercase alphabet is pressed. It should have a unique background color generated using the `key` of the `event`. It should also display the corresponding pressed character.
 - When `Backspace` is pressed, delete the last note.
 - When `Escape` is pressed, clear all the notes.