Update README.md

subjects/harder-bigger-bolder-stronger/README.md

@@ -9,7 +9,7 @@ Generate a board where each new letter is harder, bigger, bolder and stronger!
 Write the function `generateLetters` which creates 120 `div`, each containing a letter randomly picked through the **uppercase** alphabet, and whose style properties have to be increased:
 
 - each letter `font-size` has to grow from `11` to `130` pixels
-- `font-weigth` has to be `300` for the first third of the letters, `400` for the second third, and `600` for the last third
+- `font-weight` has to be `300` for the first third of the letters, `400` for the second third, and `600` for the last third
 
 ### Provided files