added whole system from ola4doc

sys/node_modules/is-utf8/README.md

@@ -0,0 +1,16 @@
+#utf8 detector
+
+Detect if a Buffer is utf8 encoded. 
+It need The minimum amount of bytes is 4.
+
+
+```javascript
+    var fs = require('fs');
+    var isUtf8 = require('is-utf8');
+    var ansi = fs.readFileSync('ansi.txt');
+    var utf8 = fs.readFileSync('utf8.txt');
+    
+    console.log('ansi.txt is utf8: '+isUtf8(ansi)); //false
+    console.log('utf8.txt is utf8: '+isUtf8(utf8)); //true
+```
+