Added more info about examples. Fix `custom-validation` example

examples/README.md

@@ -6,4 +6,27 @@ To run and development examples:
 1. Clone this repo
 2. Run `npm install`
 3. Start the development server with `npm run examples`
-4. Point your browser to http://localhost:8080
+4. Point your browser to http://localhost:8080
+
+
+## Possible Issues
+
+Examples might not run if you have an old node packages. Try clear [npm cache](https://docs.npmjs.com/cli/cache#details) and reinstall dependencies:
+```
+rm -rf node_modules
+npm cache clean
+npm install
+npm run examples
+```
+
+If it is not helped try update your node.js and npm.
+
+## Examples
+
+1. [**Login**](http://localhost:8080/login)
+
+    Two required fields with simple validation.
+
+2. [**Custom Validation**](http://localhost:8080/custom-validation)
+
+    One field with added validation rule (`Formsy.addValidationRule`) and one field with dynamically added validation and error messages. 

examples/custom-validation/app.js

@@ -18,7 +18,7 @@ var validators = {
   }
 };
 
-Formsy.addValidationRule('isYearOfBirth', function (value) {
+Formsy.addValidationRule('isYearOfBirth', function (values, value) {
   value = parseInt(value);
   if (typeof value !== 'number' || value !== value) {
     return false;