resolve crash when there a directory

src/routes/blog.rs

@@ -99,7 +99,10 @@ fn get_posts(location: &str) -> Vec<Post> {
     let entries = match std::fs::read_dir(location) {
         Ok(res) => res
             .flatten()
-            .filter(|f| f.path().extension().unwrap() == "md")
+            .filter(|f| match f.path().extension() {
+                Some(ext) => ext == "md",
+                None => false,
+            })
             .collect::<Vec<std::fs::DirEntry>>(),
         Err(_) => vec![],
     };