feat: Implement blog and blog post models, routes, and services

- Added Blog and BlogPost models with necessary fields and relationships.
- Created blogRouter for handling blog-related API endpoints including CRUD operations.
- Developed BlogService for business logic related to blogs and posts, including sharing functionality.
- Implemented API client methods for frontend to interact with blog-related endpoints.
- Added internationalization support for blog-related text in English and German.
- Created Vue components for blog editing, listing, and viewing, including a rich text editor for post content.
- Enhanced user experience with form validations and dynamic visibility settings based on user input.

backend/services/emailService.js

@@ -53,5 +53,19 @@ export const sendAnswerEmail = async (toEmail, answer, language) => {
         html: `<p>${ answer }</p>`
     };
 
+    await transporter.sendMail(mailOptions);
+};
+
+export const sendBlogShareEmail = async (toEmail, blogUrl, blogTitle, senderName) => {
+    const subject = `yourPart: ${senderName} hat einen Blog geteilt`;
+    const text = `${senderName} hat den Blog "${blogTitle}" mit dir geteilt. Du kannst ihn hier ansehen: ${blogUrl}`;
+    const html = `<p><strong>${senderName}</strong> hat den Blog "${blogTitle}" mit dir geteilt.</p><p>Hier ansehen: <a href="${blogUrl}">${blogUrl}</a></p>`;
+    const mailOptions = {
+        from: process.env.SMTP_FROM,
+        to: toEmail,
+        subject,
+        text,
+        html
+    };
     await transporter.sendMail(mailOptions);
 };