Create branch for Developer Projects starting point

[TanyaScales]

Is your feature request related to a problem? Please describe.

In order to support developers with using the CMS Boilerplate as well as Developer Projects, we want to create a starting point that they can go to and spin it up quickly.

Describe the solution you'd like

We'd like to create a permanent branch in the repo the is specifically for this purpose that houses the correct structure for Developer Projects with the CMS Boilerplate in the theme directory. Suggested branch name: cms-boilerplate-developer-projects

Additional context

For now, the app folder of the project should stay empty

Checklist

• I have read the CONTRIBUTING document.
• I have checked the issue tracker to make sure there isn’t already an open issue.

[jasonnrosa]

I tossed up a branch for this. One concern/question I would have is that for this change we move essentially all theme files into a new folder so all files will move. I haven't messed around with branches enough to know if it will continue to pick up sub-sequential updates to say src/fields.json now that the file is moved to src/theme/fields.json in this case. I have a couple updates we can test to verify though.

[jasonnrosa]

Alright this is pretty much good to go - running into a few issues when testing that I will report but besides that I think the actual work here is done.

[jasonnrosa]

Just an adjustment here - we will be moving forward without the theme folder and will be omitting hsproject.json. We'll essentially be keeping the same folder structure and just be swapping files with HubL over to .hubl. extensions.

[jasonnrosa]

Going to close this out given the branch is ready (#404) but it won't be merged so this would be considered done for the time being.