fix: look for proxy headers first when building url for rss fed

src/Blog/Program.cs

@@ -27,7 +27,11 @@ app
   .MapGet("/rss", async (HttpContext context, IPostService postService) =>
   {
     var req = context.Request;
-    var url = $"{req.Scheme}://{req.Host}{req.PathBase}";
+
+    var scheme = req.Headers["X-Forwarded-Proto"].FirstOrDefault() ?? req.Scheme;
+    var host = req.Headers["X-Forwarded-Host"].FirstOrDefault() ?? req.Host.Value;
+
+    var url = $"{scheme}://{host}{req.PathBase}";
 
     var posts = await postService.GetPostsAsync();