Support JSON/YAML format for config

**Is your feature request related to a problem? Please describe.**
It's hard write configs without having any sort of intellisence. YAML/JSON files have good enough [LSP](https://marketplace.visualstudio.com/items?itemName=redhat.vscode-yaml) for VS Code:


**Describe the solution you'd like**
Add support for JSON/YAML formats for config until ron gets intellisence support like JSON/YAML where user can create any arbitrary schemas and associate them with any files.

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context**
Besides, I am suggesting this feature as I [can](https://github.com/SchemaStore/schemastore/pulls/EmilySeville7cfg) write JSON schemas and could add a new one for yours config if JSON/YAML formats were supported.

La issue non indica file, test o punti di ingresso. Inizia individuando come gitui legge attualmente la configurazione e determina i formati JSON/YAML previsti e il comportamento di associazione dello schema; il lavoro è completato quando entrambi i formati sono supportati con l’intelligenza dell’editor richiesta.

Scritto dal modello di indicizzazione a partire dal testo della issue.