Feature: schema validation for blocky configuration

[speedst3r]

When editing YAML documents, it is often helpful to have application specific linting and validation, such as the case with Frigate (https://docs.frigate.video/configuration/#vscode-configuration-schema).

I have cut a first draft of a schema for Blocky's configuration (by no means final, and not heavily tested) and am gauging whether there would be interest in this. An example in code-server with the YAML Language Server plugin is below (this would look similar in VSCode)

The current schema is in my fork - https://raw.githubusercontent.com/speedst3r/blocky/refs/heads/json-schema/config/schema.json

If there's appetite to include this I'd be happy to raise a PR.

[0xERR0R]

I think, providing a JSON schema for the config file is a good idea. We can also use it for config validation on startup (if it provides more readable messages)