Generate documentation for default builders

AIO has a page on `angular.json` workspace configuration which lists [default builders](https://angular.io/guide/workspace-config#default-architect-builders-and-targets). Unfortunately these builders link directly to the [JSON schema](https://github.com/angular/angular-cli/blob/main/packages/angular_devkit/build_angular/src/builders/browser/schema.json), which is not very intuitive.

We should process these schema files and generate a page for each builder linked from the workspace configuration. This would make it much easier to understand `@angular-devkit/build-angular` and related builders' options.

Start with the AIO workspace configuration page and the linked default builder schema, packages/angular_devkit/build_angular/src/builders/browser/schema.json. Trace how the schema files could be processed into documentation pages and linked from the default builders list. Done means each relevant builder has an understandable generated page and the workspace configuration links to those pages instead of directly to JSON schemas.

Written by the indexing model from the issue text.