Write a doc page for javascript lambda

[zeppaman]

Describe javascript APIs:

• wich methods are available
• how it works with some example

For what we have so far we should include examples:

• Http request (a post and get)
• CRUD ( insert\update, delete, query, count)

[tokarzkj]

@zeppaman - I can grab this one if no one has been assigned. I implemented the Javascript feature, so I should be able to create some decent examples.