feat(docs): add copy buttons to markdown code blocks

Add copy functionality to all code blocks in documentation markdown content.
Previously, only example viewer code and module import snippets had copy
buttons, but regular markdown code blocks (like configuration examples)
were missing this feature.

Author: MeAkib

docs/src/app/shared/doc-viewer/code-block-copy-button/code-block-copy-button.ts

@@ -17,7 +17,7 @@ import {Clipboard} from '@angular/cdk/clipboard';
   selector: 'code-block-copy-button',
   imports: [MatIconButton, MatIcon, MatTooltip],
   template: `
-    <button role="button" type="button" mat-icon-button matTooltip="Copy code to the clipboard" (click)="copy()">
+    <button mat-icon-button matTooltip="Copy code to the clipboard" (click)="copy()">
       <mat-icon>content_copy</mat-icon>
     </button>
   `,