Change config file format

[goodboy]

After some thinking I believe using
toml for both the current bokers.ini
and watchlists.json files is probably the easiest and
simplest way forward. There are some competitors (particularly for a DSL
that supports referencing / copying / merging content for the purposes
of watchlists) as detailed below.

We also have an open issue on choosing a better toml client lib
as per #496. Also pertains to #68.

Note TOML doesn't support - <value> style document array/lists and
instead somewhat enforces keying everything:
https://toml.io/en/v1.0.0#keys

versus something like (ugh-ish) yaml:

• https://quickref.me/yaml

---

Alt langs / formats

Some other options i haven't had time to dig into yet:

• dhall programmable config files

  • haskell DSL with quite a few fancy features
  • https://github.com/Nadrieril/dhall-rust
  • https://github.com/dhall-lang/dhall-lang/blob/master/README.md
  • https://learnxinyminutes.com/docs/dhall/

• eno is a type agnostic nex-gen data markup lang, see the spec

  • main holdup for me (other then not being sure if it's much better then TOML) was that there's no vim syntax highlight plugin..
  • https://github.com/eno-lang
  • https://codeberg.org/simonrepp/enolib-py
  • https://eno-lang.org/python/querying-content/field-values/
  • https://vi.stackexchange.com/questions/29545/language-specific-custom-syntax-highlighting
  • https://www.vimregex.com/
  • https://github.com/simonrepp
  • https://codeberg.org/simonrepp
  • https://github.com/eno-lang/benchmarks/
  • https://github.com/topics/vim-syntax-highlighting
  • https://eno-lang.org/blog/
  • https://codeberg.org/simonrepp/faircamp
  • https://eno-lang.org/guide/faq/