chore: reworking the initial work to link out to the sign in reolver

Signed-off-by: blam <ben@blam.sh>

docs/getting-started/configuration.md

@@ -187,55 +187,7 @@ components: {
  },
 ```
 
-Since [v1.1.0](https://github.com/backstage/backstage/releases/tag/v1.1.0-next.3), you must provide an explicit sign-in resolver.
-
-Open `packages/backend/src/plugins/auth.ts` and replace with following code snippet:
-
-```typescript
-import {
-  createRouter,
-  providers,
-  defaultAuthProviderFactories,
-} from '@backstage/plugin-auth-backend';
-import { Router } from 'express';
-import { PluginEnvironment } from '../types';
-import { stringifyEntityRef } from '@backstage/catalog-model';
-
-export default async function createPlugin(
-  env: PluginEnvironment,
-): Promise<Router> {
-  return await createRouter({
-    ...env,
-    providerFactories: {
-      ...defaultAuthProviderFactories,
-      github: providers.github.create({
-        signIn: {
-          resolver: async ({ profile }, ctx) => {
-            if (!profile.email) {
-              throw new Error(
-                'Login failed, user profile does not contain an email',
-              );
-            }
-            const [localPart] = profile.email.split('@');
-
-            const userEntityRef = stringifyEntityRef({
-              kind: 'User',
-              name: localPart,
-              namespace: 'DEFAULT_NAMESPACE',
-            });
-            return ctx.issueToken({
-              claims: {
-                sub: userEntityRef,
-                ent: [userEntityRef],
-              },
-            });
-          },
-        },
-      }),
-    },
-  });
-}
-```
+> Since [v1.1.0](https://github.com/backstage/backstage/releases/tag/v1.1.0-next.3), you must provide an [explicit sign-in resolver](https://backstage.io/docs/auth/identity-resolver).
 
 That should be it. You can stop your Backstage App. When you start it again and
 go to your Backstage portal in your browser, you should have your login prompt!