Documentation about pybamm-cookiecutter

[agriyakhetarpal]

A placeholder issue for keeping track of documentation-related tasks.

• Set up an initial draft for documentation pages for the project: installation, technical details, user guide, adding data paths, adding parameter sets, and more
• Surrounding infrastructure for building the documentation locally (tracked by Add templates and configuration for documentation #4)
• In the project's documentation: a basic guide to using Sphinx, adding example notebooks and scripts, adding thumbnail galleries, adding a references page, troubleshooting, and FAQs.
  • Possibly, some utility functions for registering citations in both code and documentation, similar to PyBaMM's citation workflow
• Surrounding infrastructure for deploying the documentation on Read the Docs in the CI. It should have PR builds on each commit, cancelling the build on subsequent pushes to a branch

See also: #1