update example and documentation to show usages of exclude option

.verb.md

@@ -80,7 +80,16 @@ Define a custom string to be randomized.
 * `randomize('?', 20, {chars: 'jonschlinkert'})` will generate a 20-character randomized string from the letters contained in `jonschlinkert`.
 * `randomize('?', {chars: 'jonschlinkert'})` will generate a 13-character randomized string from the letters contained in `jonschlinkert`.
 
+#### exclude
+Type: `String|Array`
 
+Default: `undefined`
+
+Specify a string or array of characters can are excluded from the possible characters used to generate the randomized string.
+
+**Example:**
+
+* `randomize('*', 20, { exclude: '0oOiIlL1' })` will generate a 20-character randomized string using all of possible characters except for `0oOiIlL1`.
 
 ## Usage Examples
 

examples.js

@@ -80,6 +80,10 @@ function parse(args) {
   });
 }
 
+console.log();
+console.log(rand('*', 20, { exclude: '0oOiIlL1' }));
+console.log();
+
 // function parse(args) {
 //   return args.map(function(arg) {
 //     if (/\{/.test(arg)) {