Add /log page that displays server log

This will eventually be behind an authorization guard so that only I
have access, but it's useful to have for monitoring and testing out
turbo streams.

src/handlers/log.rs

@@ -0,0 +1,13 @@
+use axum::response::Response;
+use maud::html;
+
+use crate::error::Result;
+use crate::partials::layout::Layout;
+use crate::log::MEM_LOG;
+
+pub async fn get(layout: Layout) -> Result<Response> {
+    let mem_buf = MEM_LOG.lock().unwrap();
+    Ok(layout.render(html! {
+        pre { (std::str::from_utf8(mem_buf.as_slices().0).unwrap()) }
+    }))
+}

src/handlers/mod.rs

@@ -2,3 +2,4 @@ pub mod api;
 pub mod entry;
 pub mod home;
 pub mod feeds;
+pub mod log;