apiDoc added in list

[manishsaraan]

Before creating a pull-request, please check https://github.com/wycats/handlebars.js/blob/master/CONTRIBUTING.md first.

Generally we like to see pull requests that

• [x ] Maintain the existing code style
• Are focused on a single change (i.e. avoid large refactoring or style adjustments in untouched code if not the primary goal of the pull request)
• Have good commit messages
• Have tests
• Don't significantly decrease the current code coverage (see coverage/lcov-report/index.html)

[manishsaraan]

@nknapp I have added apiDoc in Handlebars in the Wild section. Please have a look.