Add support of Cloudflare Web Analytics (#492)

YUJI

15.38.2020 dbe21a7fdf0d5556de5b2f2f8bdf4f64228ca241

 stackbit.yaml

@@ -137,6 +137,13 @@
              - type: string
                name: code
                label: URL for Goat Counter
          - type: object
            name: cloudflare
            label:  Cloudflare Web Analytics (optional)
            fields:
              - type: string
                name: token
                label: token for Cloudflare Web Analytics
      - type: object
        name: languages
        fields: