k-local Ising wrapper for QAOA

[markf94]

This PR implements the following changes:

• implements support for k-local Ising instances
• fixes several bugs that occured with Ising instances that didn't have bias (h) terms for each qubit
• introduces proper Read the Docs for the Ising QAOA wrapper
• introduces a new parameter driver_operators for ising_qaoa() in order to allow for manual definition of the QAOA mixer hamiltonian
• renames ising() to ising_qaoa()

[markf94]

@ampolloreno Semaphore build fails due to unrelated issues with Tomography.

[ampolloreno]

@markf94 Awesome! I'll get to looking at this again soon!