Pyvmcon

What's Changed
* Optimisation, improved typing, docstring spelling mistakes by je-cook in https://github.com/ukaea/PyVMCON/pull/12

Fix a bug in the `B` (Hessian approximation) matrix where the size was set to the max of `n` or `m` (a relic from a long time ago in development).

Add a callback which is called on each iteration. E.g. can be used to print convergence information on each iteration

What's Changed
* `qsp_tolerence` keyword argument replaced by `qsp_options` dictionary (https://github.com/ukaea/PyVMCON/pull/7).

Initial release of PyVMCON.