add urlsafe parameter

README.md

@@ -1,5 +1,33 @@
 # securerandomstring
 a node module that generates a secure random string with a given length
 
-## usage
-see `tests.js`
+## Usage
+`require` it
+
+```
+var securerandomstring = require('securerandomstring');
+```
+
+
+generate a random string that is 32 chars long (the default)
+```
+securerandomstring(function(sr) {
+	console.log(sr);
+});
+```
+
+
+generate a random string that is 256 chars long
+```
+securerandomstring({length: 256}, function(sr) {
+	console.log(sr);
+});
+```
+
+
+generate a random string that is 20 chars long and is url safe (can be used as a url token)
+```
+securerandomstring({length: 20, urlsafe: true}, function(sr) {
+	console.log(sr);
+});
+```