Add API to set product name for crash reporter.

docs/api/common/crash-reporter.md

@@ -4,11 +4,16 @@ An example of automatically submitting crash reporters to remote server:
 
 ```javascript
 crashReporter = require('crash-reporter');
+crashReporter.setProductName('YourName');
 crashReporter.setCompanyName('YourCompany');
 crashReporter.setSubmissionUrl('https://your-domain.com/url-to-submit');
 crashReporter.setAutoSubmit(true);
 ```
 
+## crashReporter.setProductName(product)
+
+* `product` String
+
 ## crashReporter.setCompanyName(company)
 
 * `company` String