* Added ``pyproximal.optimization.primal.ADMML2``,
`pyproximal.optimization.primal.HQS`,
and ``pyproximal.optimization.pnp.PlugAndPlay`` solvers
* Added ``pyproximal.proximal.ETP``, ``pyproximal.proximal.Geman``,
``pyproximal.proximal.L0`, ``pyproximal.proximal.Log``,
``pyproximal.proximal.QuadraticEnvelopeCard``, ``pyproximal.proximal.SCAD``
operators.
* Allow ``tau`` parameter of proximal operators to be a vector to handle problems with
multiple right-hand sides.