docs: merge authentication.md into README.md and let people know they should report issues on Umbraco-CMS

Author: iOvergaard

.github/README.md

@@ -29,9 +29,6 @@ The development environment is the default environment and is used when running
 
 ### Run against a local Umbraco instance
 
-> **Note**
-> Make sure you have followed the [Authentication guide](https://github.com/umbraco/Umbraco.CMS.Backoffice/blob/main/docs/authentication.md) before continuing.
-
 If you have a local Umbraco instance running, you can use the development environment to run against it by overriding the API URL and bypassing the mock-service-worker in the frontend client.
 
 Create a `.env.local` file and set the following variables:
@@ -41,14 +38,37 @@ VITE_UMBRACO_API_URL=https://localhost:44339 # This will be the URL to your Umbr
 VITE_UMBRACO_USE_MSW=off # Indicate that you want all API calls to bypass MSW (mock-service-worker)
 ```
 
+Open this file in an editor: `src/Umbraco.Web.UI/appsettings.Development.json` and add this to the `Umbraco:CMS:Security` section to override the backoffice host:
+
+```json
+"Umbraco": {
+	"CMS": {
+		"Security":{
+			"BackOfficeHost": "http://localhost:5173",
+			"AuthorizeCallbackPathName": "/oauth_complete",
+			"AuthorizeCallbackLogoutPathName": "/logout",
+			"AuthorizeCallbackErrorPathName": "/error",
+		},
+	},
+}
+```
+
+Now start the vite server: `npm run dev:server` in your backoffice folder and open the http://localhost:5173 URL in your browser.
+
 ### Storybook
 
 Storybook is also being built and deployed automatically on the Main branch, including a preview URL on each pull request. See it in action on this [Azure Static Web App](https://ambitious-stone-0033b3603.1.azurestaticapps.net/).
 
+You can test the Storybook locally by running `npm run storybook`. This will start the Storybook server and open a browser window with the Storybook UI.
+
+Storybook is an excellent tool to test out UI components in isolation and to document them. It is also a great way to test the responsiveness and accessibility of the components.
+
 ## Contributing
 
-We accept contributions to this project. However be aware that we are mainly working on a private backlog, so not everyone will be immediately obvious. If you want to get started on contributing, please read the [contribute space](https://github.com/umbraco/Umbraco.CMS.Backoffice/contribute) where you will be able to find the guidelines on how to contribute as well as a list of good first issues.
+We accept contributions to this project. However be aware that we are mainly working on a private backlog, so not everything will be immediately obvious. If you want to get started on contributing, please read the [contributing guidelines](./CONTRIBUTING.md).
+
+A list of issues can be found on the [Umbraco-CMS Issue Tracker](https://github.com/umbraco/Umbraco-CMS/issues). Many of them are marked as `community/up-for-grabs` which means they are up for grabs for anyone to work on.
 
 ## Documentation
 
-The documentation can be found on [Umbraco Docs](https://docs.umbraco.com/umbraco-backoffice/). The documentation is a work in progress.
+The documentation can be found on [Umbraco Docs](https://docs.umbraco.com/umbraco-cms).