Adjusting the allowed fit parameter ranges command line option(s)

[fjankowsk]

The predefined fit parameter (amplitude, centre, sigma, or taus) ranges are currently tuned towards MeerKAT FRB data at L-band frequencies. The allowed ranges are sometimes too narrow for very strongly scattered pulsars or some particular FRBs. Changing them requires editing the code, which could be better. Please see here:

https://scatfit.readthedocs.io/en/latest/FAQ.html#what-should-i-do-if-some-distributions-in-the-mcmc-corner-plots-look-artificially-cut-off

It would be great if someone could add command line option(s) to allow user to adjust the allowed fit parameter ranges. This should be reasonably easy, but it requires a bit of thought on how to do it most sensibly.