docs: refactoring doc scripts

[callmehiphop]

closes #1618

This essentially let's us generate JSON for arbitrary releases since we often can't count on Travis to do this in a timely fashion.

Example:

$ npm run docs bigquery 0.6.0

The script does not automatically commit/push anymore however. This will be up to the user to manually do (I still need to tie this into our .travis.yml) and they'll also have to clean up the submodule used to push the docs.

[stephenplusplus]

Does this resolve #1618?

[callmehiphop]

@stephenplusplus I think this should be good to go if you care to take a look!

[stephenplusplus]

If this resolves #1618, can you outline what the workflow is for updating the docs website is and pop it in CONTRIBUTING?

[callmehiphop]

@stephenplusplus I've updated the CONTRIBUTING guide, you can preview it on my fork.

[stephenplusplus]

Thank you, the write up is awesome. But, is it possible to have a command that does all that for us, right up until the git push?

[callmehiphop]

So you want to automate this

$ git submodule add -b gh-pages git@github.com:GoogleCloudPlatform/google-cloud-node.git
$ rm -rf docs/json
$ npm run docs google-cloud 0.43.0
$ cp -rf docs/json/* gh-pages/json
$ cp docs/manifest.json gh-pages
$ cd gh-pages
$ git add .
$ git commit -m 'Update docs for google-cloud 0.43.0 [ci skip]'

?

[stephenplusplus]

Yeah, one command and then manual push to origin.

[callmehiphop]

Done, PTAL.

[callmehiphop]

Does this resolve #1618?

Yep