Correct typo "Commmand" -> "Command"

Working-for-Web-(HTML5).md

@@ -173,7 +173,7 @@ raylib examples [`Makefile`](https://github.com/raysan5/raylib/blob/master/examp
 
 ## 4. Compile raylib game for web
 
-### 4.1 Commmand-line compilation
+### 4.1 Command-line compilation
 
 To compile raylib game directly from the command line, those are the commands to run: