Code style guide and microsite production handbook

[jeremydw]

We should have a code and project style guide that recommends a best practice for building a standard website with Grow. The idea is that new developers can reference this style guide, we can share this style guide with major users of Grow, and we can include a link to this style guide in the README of Grow projects.

An idea is that whenever you jump into a Grow project you will feel "at home" with respect to the project structure.

@uxder - can you pick up the style guide from where I left off and add in anything I haven't written yet? The initial work I started is here in this branch - https://github.com/grow/grow.io/tree/styleguide

In addition to the style guide, we should also eventually have a "microsite production handbook" that details the project lifecycle from a high level. The handbook should include a brief overview of all the steps of a typical marketing project (discovery, kickoff, build, review, LQA, review, launch, repeat + maintain, etc.) as well as conventions around branch naming strategies, staging, etc.

The handbook can also include tools and recommendations that we may use for projects - e.g. svgo for SVG minification, airkit, GCS for asset hosting, and a theoretical image upload tool that we can build to upload images to Google's image hosting service (https://cloud.google.com/appengine/docs/standard/python/images/#get-serving-url) which can resize and crop images dynamically based on query params.

With these two things - the styleguide and microsite production handbook - we can empower Grow users as well as our team with a canonical resource for understanding the project lifecycle from both a tech and process standpoint.

/cc @adelaidemt, @Zoramite, @stevenle as FYI

[uxder]

Sounds good. I'll start with tackling the styleguide :)