feat(dprint): allow custom options for external formatters

[folliehiyuki]

... by making the settings option a freeformType.

Fixes #149.

[zimbatm]

@mergify merge

[mergify[bot]]

merge

❌ Sorry but I didn't understand the command. Please consult the commands documentation 📚.

[zimbatm]

@mergify queue

[mergify[bot]]

queue

🛑 Command queue cancelled because of a new queue command with different arguments

[zimbatm]

@mergify rebase

[mergify[bot]]

rebase

☑️ Nothing to do

- [ ] `queue-position=-1` [📌 rebase requirement] - [X] `-closed` [📌 rebase requirement] - [X] `-conflict` [📌 rebase requirement] - [X] any of: - [X] `#commits>1` [📌 rebase requirement] - [X] `-linear-history` [📌 rebase requirement] - [ ] `#commits-behind>0` [📌 rebase requirement]

[zimbatm]

@mergify queue

[mergify[bot]]

queue

🟠 Waiting for conditions to match

- [ ] any of: [🔀 queue conditions] - [ ] all of: [📌 queue conditions of queue `default`] - [ ] any of: [🛡 GitHub branch protection] - [ ] `check-neutral=buildbot/nix-eval` - [ ] `check-skipped=buildbot/nix-eval` - [ ] `check-success=buildbot/nix-eval` - [X] `-draft` [📌 queue requirement] - [X] any of: [📌 queue -> configuration change requirements] - [X] `-mergify-configuration-changed` - [ ] `check-success=Configuration changed`