feat: validate biome.json path config

[victor-teles]

This PR closes #5.

• Now the field has support for directory and file.
• It now validates existence os biome.json file

[ematipico]

I'm still not sure how this is going to work, but users should just pass a file name, but only the directory where the configuration is. Biome will do the rest

[ematipico]

I'm not sure this will work in the long run. Once we allow biome.jsonc as a configuration file format, this will be outdated and will require a new version.

I'm not sure it's worth it

[victor-teles]

Nice, I'll update to a more flexible approach

[victor-teles]

I'm still not sure how this is going to work, but users should just pass a file name, but only the directory where the configuration is. Biome will do the rest

@ematipico You mean there's no need to validate the input?

Just to give you some context:
Before this PR, if the user select the biome.json file in this field, the plugin will pass the value to CLI using --config-path flag and this will result in an error: Biome couldn't read the following file, maybe for permissions reasons or it doesn't exist: /path/project/biome.json/rome.json

To fix this i now just pass the parent path: /path/project instead of /path/project/biome.json

[ematipico]

Thank you, it wasn't clear from the PR description