Add structured data info (JSON LD or Microdata)

[stefanb]

Unrelated to basic #36 we could annotate per-doctor page with microdata for their

• contact (name, occupation. address, phone...)
• location (latitude and longitude)
• ...

Either as JSON-LD or Microdata

https://developers.google.com/search/docs/advanced/structured-data/intro-structured-data
https://w3c.github.io/json-ld-bp/
https://www.npmjs.com/package/jsonld

[jalezi]

I have tried with helmet which we are already using.

Example is on doctor-page-seo branch.

I guess it works but I'm JSON-LD noob.