[che-docs] Automatically generate documentation with the list of supported plugins after each Che release

Is your task related to a problem? Please describe.

The issue is inspired by https://github.com/eclipse/che-docs/pull/1041 Currently, it is not straight forward to get information about supported plugins, languages, debuggers supported in Che. This info is located in the che-plugin-registry - https://github.com/eclipse/che-plugin-registry/tree/master/v3/plugins and currently docs do not contain any information about the supported plugins.

Describe the solution you’d like / User Stories

• As a user, I want to have up-to-date information about the supported plugins
• As a developer, I want to have the adoc with supported plugins automatically generated

Describe alternatives you’ve considered

Manual creation of the doc which is error-prone and get obsolete really fast

Additional context

Potential implementation details

• adoc is generated from the https://github.com/eclipse/che-plugin-registry/tree/master/v3/plugins
• meta.yaml for each plugin has a relevant category e.g. Language / Debugger

[ericwill]

We have an automated report that lists all plugins in the registry, as well as what version is in the registry and what version is available upstream. The report is updated every time a change is merged.

https://eclipse.github.io/che-plugin-registry/

[ericwill]

We can do both!