derivepassphrase.git

1) ### Added
2) 
3)   - `derivepassphrase` now uses a central configuration file, and additional
4)     data files, some of which are service-specific.  (The `vault.json`
5)     configuration file is now rebranded as a data file.)  The configuration
6)     files are user-editable, the data files are `derivepassphrase`-editable.
7) 
8)     The configuration files are in TOML format, so installing

9)     `derivepassphrase` on Python 3.10 and older requires the
10)     [`tomli`][tomli] package.