Pyhdx process cli interface

It should be possible to invoke pyhdx from the command line

Something like:

```
$ pyhdx process
```

where `data_spec ` specifies files / temperature / pH etc, where files should be in the same directory
and `jobfile` specifies which type of fitting to do

Start by locating the pyhdx command entry point and review how the proposed `pyhdx process ` invocation could map to the existing processing flow. Clarify the expected fields for both YAML files, then consider the work complete when the command accepts them and performs the requested fitting type using the specified files and conditions.

索引モデルが issue の本文から書いたものです。