Add schemas

[alvaromartmart]

It is possible to use JSON schemas to validate the YML files, which would make it much easier to author these.

I don't have too much experience with YML validation tooling, but I have managed to set up some basic integration in VSCode, involving:

• Creating a seqera-kit.schema.json declaring the valid properties for organizations, e.g.

  {
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "seqerakit yml file",
  "type": "object",
  "properties": {
      "organizations": {
          "description": "Organizations",
          "type": "array",
          "items": {
              "type": "object",
              "properties": {
                  "name": {
                      "type": "string",
                      "description": "Name of the organization"
                  },
                  "full-name": {
                      "type": "string",
                      "description": "Full name"
                  },
                  "description": {
                      "type": "string",
                      "description": "Description of the organization"
                  },
                  "location": {
                      "type": "string",
                      "description": "Description of the organization"
                  },
                  "website": {
                      "type": "string",
                      "description": "Website"
                  },
                  "overwrite": {
                      "type": ["boolean", "string"],
                      "description": "Overwrite the organization if it already exists"
                  }
              },
              "required": ["name"]
          }
      }
  }
  }

• Telling VSCode which local json.schema file to use to validate specific .yml files:

  "settings": {
      "yaml.schemas": {
          "file:///seqera-kit.schema.json": "seqera-kit/**.yml"
      },