Quick How-Tos for PreTeXt quickstart

[hammadmazhar1]

There should be small 5-10 min quickstart guides to have new users get started with PreTeXt, on their machine locally and on their document of choice. Ideally such guides include code examples that users can copy/paste into their terminals/documents, a
nd structured as:

1. Installing PreText-CLI (list dependencies)
2. Create PreTeXt project with CLI for requisite document
   a. Include document specific schema tags with illustrative code examples
3. Describe document structure e.g. front matter, back matter, body with pointers to where they lie in project directory
4. Describe how to build/view/deploy project, showing WHERE the output lies (so someone can take the output and hand it over to their IT department for instance)
5. Describe 'embeddables' and have code examples for inserting them.
6. Sharing PreTeXt project source with other collaborators (not HTML)

As an additional 'ask', we could have some form of script that can do the legwork of this that a user just downloads and runs and gets what they need. A rudimentary example is here that installs Python, PreTeXt CLI, VS Code (if not present) and a given template from a repo and displays it to the user in the text editor.