Disable spellcheck to remove red squiggles.

src/Editor.tsx

@@ -42,6 +42,7 @@ function Editor({
         className={styles.EditorTextArea}
         value={value}
         onScroll={onTextAreaScroll}
+        spellCheck={false}
       />
       <div ref={shadowRef} className={styles.EditorUnderlay}>
         {buildShadow(highlights, value)}