Missing Resource Types

[em3697]

Hi, I'm using this repo's latest version to generate a Looker Studio report, but out of the box use with our FHIR data resulted in some errors with ServiceRequest amongst other resources. I saw the resource list in fhir_sources.yml and assumed that would be the spot to add any additional resources our data has. Looks like it is resolving some of those errors, but wanted to mention it here in case there are additional files in the repo that may be impacted by such changes, or a better way to address additional resource types, or you want to add it to documentation. Thanks!