fixing typo in style sheet

Author: howcome

css-gcpm/Overview.src.html

@@ -12,7 +12,7 @@
 .example img { display: block }
 .example { background: #ddd }
 body { line-height: 1.3 }
-.unimplmented { background: #fee }
+.unimplemented { background: #fee }
 </style>