Update project to meet the standards of Pallets

[kblomqvist]

Yasha is heavily based on Pallets Projects (Jinja2 and Click). I have also seen that there is (some) need for the Yasha kind of tool among the users of Jinja2. Thus, it would be nice to have the project listed in Pallets. Before making a proposal, make sure that at least the following requirements are met.

• Configuration, https://github.com/pallets/meta/issues/23.
• Readthedocs documentation.
• Implement Move SVD parser to its own installable module #17. The projects should concentrate on the essentials and not support rather rare use cases.
• Check coding standards.