refactor(preview): only show project preview if it exists

Author: rainwithcode

src/components/projects.astro

@@ -76,7 +76,7 @@ const projects: Project[] = [
                       <path d="M24 12L18.3431 17.6569L16.9289 16.2426L21.1716 12L16.9289 7.75736L18.3431 6.34315L24 12ZM2.82843 12L7.07107 16.2426L5.65685 17.6569L0 12L5.65685 6.34315L7.07107 7.75736L2.82843 12ZM9.78845 21H7.66009L14.2116 3H16.3399L9.78845 21Z" />
                     </svg>
                   </a>
-                  <a
+                  {project.preview && <a
                     target="_blank"
                     href={project.preview}
                     aria-label="Preview"
@@ -90,7 +90,7 @@ const projects: Project[] = [
                     >
                       <path d="M16.0037 9.41421L7.39712 18.0208L5.98291 16.6066L14.5895 8H7.00373V6H18.0037V17H16.0037V9.41421Z" />
                     </svg>
-                  </a>
+                  </a>}
                 </div>
               </div>
             </a>