chore: Remove Storybook MDX documentation

The mdx documentation is not actively maintained and outdated.
The main purpose was to get an overview over active stories, but this
is covered by the PR integration of reg-actions.

docs/docs/development/frontend/storybook.md

@@ -53,50 +53,18 @@ import { Meta, moduleMetadata, StoryObj } from '@storybook/angular';
 import { Component } from './component-name.component';
 
 const meta: Meta<YourComponent> = {
-  title: 'Your Component',
-  component: YourComponent,
+    title: 'Your Component',
+    component: YourComponent,
 };
 
 export default meta;
 type Story = StoryObj<YourComponent>;
 
 export const ExampleStory: Story = {
-  args: {
-    ...
-  },
+    args: {},
 };
 ```
 
-## Add documentation for the Story
-
-In the same directory of the component, add a file `{component_name}.docs.mdx`
-and use the following code as a template:
-
-```mdx
-import * as Component from './component-name.stories.ts';
-import { Meta, Title, Story, Canvas, Unstyled } from '@storybook/blocks';
-
-<Meta of={Component} />
-
-<Title />
-
-This is an example story for the component:
-
-<Story of={Component.ExampleStory} />
-```
-
-If you want to use `HTML` in your template, you can use the `Unstyled` block.
-In the example, we wrap the story in a `div` to show how it behaves on smaller
-devices:
-
-```mdx
-<Unstyled>
-    <div style={{ width: '500px' }}>
-        <Story of={Component.ExampleStory} />
-    </div>
-</Unstyled>
-```
-
 ## Mock Angular services
 
 You can mock services with the `moduleMetadata` decorator in Storybook. Here is
@@ -105,31 +73,31 @@ access levels:
 
 ```js
 class MockProjectUserService implements Partial<ProjectUserService> {
-  role: ProjectUserRole
+    role: ProjectUserRole;
 
-  constructor(role: ProjectUserRole) {
-    this.role = role
-  }
+    constructor(role: ProjectUserRole) {
+        this.role = role;
+    }
 
-  verifyRole(requiredRole: ProjectUserRole): boolean {
-    const roles = ['user', 'manager', 'administrator']
-    return roles.indexOf(requiredRole) <= roles.indexOf(this.role)
-  }
+    verifyRole(requiredRole: ProjectUserRole): boolean {
+        const roles = ['user', 'manager', 'administrator'];
+        return roles.indexOf(requiredRole) <= roles.indexOf(this.role);
+    }
 }
 
+const mockProjectUserServiceProvider = (role: ProjectUserRole) => {
+    return {
+        provide: ProjectUserService,
+        useValue: new MockProjectUserService(role),
+    };
+};
+
 export const ExampleStory: Story = {
-  args: {
-    ...
-  },
-  decorators: [
-    moduleMetadata({
-      providers: [
-        {
-          provide: ProjectUserService,
-          useFactory: () => new MockProjectUserService('user'),
-        },
-      ],
-    }),
-  ],
-}
+    args: {},
+    decorators: [
+        moduleMetadata({
+            providers: [mockProjectUserServiceProvider('user')],
+        }),
+    ],
+};
 ```