As a plugin owner/author, I would like to be able to know if my plugin is running on RHDH or vanilla Backstage for analytics purpose.

As a plugin owner/author, I would like to be able to know which Backstage I'm running on (e.g. OSS, RHDH, RHTAP, others**), so I can display more information if needed. For example, the Tekton plugin should display the security vulnerabilities only if it's on RHTAP but not RHDH and OSS.

**Partners such as Deloitte and IBM will also need to use this feature as well for their respective offerings.

• add a new configuration key called `developerHub->flavor` to the RHDH configuration file https://github.com/janus-idp/backstage-showcase/blob/main/app-config.yaml
• the value should be `rhdh`
• add the configuration to our schema https://github.com/janus-idp/backstage-showcase/blob/main/packages/app/config.d.ts#L3
• provide example code how to query that configuration in our plugins developer documentation