Update PDF Viewer docs with examples and image URLs

Updated `<img>` tags in the documentation to include valid GitHub-hosted URLs. Added examples for handling password-protected PDFs in the `<PdfViewer>` component, including setting the `Password` parameter and prompting users for a password. Enhanced `alt` attributes for better visual representation of features.

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Author: gvreddy04

docs/docs/05-components/pdf-viewer.mdx

@@ -155,7 +155,7 @@ Below screenshot is added for demo purposes only. For additional info, refer to
 
 To open a password-protected PDF document, set the <code>Password</code> parameter to the required password.
 
-<img src="" alt="Blazor Bootstrap: Blazor PDF Viewer Component - Password protected" />
+<img src="https://github.com/user-attachments/assets/92e6634a-eedd-4ad5-b067-858d2cd2282a" alt="Blazor Bootstrap: Blazor PDF Viewer Component - Password protected" />
 
 ```cshtml {} showLineNumbers
 <PdfViewer Class="mb-3"
@@ -170,7 +170,7 @@ To open a password-protected PDF document, set the <code>Password</code> paramet
 If the <code>Password</code> parameter is not set and the PDF document is password-protected, the PDF Viewer component will prompt the user to enter the password.
 In the following example, the PDF Viewer prompts the user to enter the password for the protected PDF document. Enter <b>12345</b> as the password to view the document.
 
-<img src="" alt="Blazor Bootstrap: Blazor PDF Viewer Component - Prompt for password" />
+<img src="https://github.com/user-attachments/assets/ba4d7a9f-fea7-451e-b31d-72af5d03569e" alt="Blazor Bootstrap: Blazor PDF Viewer Component - Prompt for password" />
 
 ```cshtml {} showLineNumbers
 @if (showPdfViewer)