The form fields configuration is used for creating backend forms

fields.yaml schema URL:

https://raw.githubusercontent.com/inetis-ch/october-schemas/master/fields.json

October CMS documentation

The column configuration is used for creating backend record list

columns.yaml schema URL:

https://raw.githubusercontent.com/inetis-ch/october-schemas/master/columns.json

October CMS documentation

Open Settings/Preferences dialog, go to Languages & Frameworks | Schemas and DTDs | JSON Schema Mappings.
Add new json schema and specify :

• a name (what you want)
• the URL (see above),
• schema version 7

add mapping "file path pattern" and set the file name (e.g. fields.yaml)

Documentation

• Install YAML extension by Red Hat
• Open your settings.json file and add following:

{
    "yaml.schemas": {
        "https://raw.githubusercontent.com/inetis-ch/october-schemas/master/fields.json": [
            "fields.yaml"
        ],
        "https://raw.githubusercontent.com/inetis-ch/october-schemas/master/columns.json": [
            "columns.yaml"
        ]
    }
}