Soft docs "Wishlist"

[JGrantHill]

Additional docs that sit between the quick start guide and the API docs would be useful for users who are less familiar with Python and API documentation. Possible topics to consider.

• More on providing / fetching / importing basis set.
• Printing and exporting basis sets.
• Using different starting guesses.
• Specifying basis set composition / quality.
• Further documentation on different Strategies.
• Using preconditioners and regularisers.