Embed algo.md at compile time to fix prod 500

algo.md was read at runtime via File.read! but isn't included in
the release. Use @external_resource + compile-time module attribute
to bake the HTML into the module.

lib/microwaveprop_web/live/algo_live.ex

@@ -2,16 +2,12 @@ defmodule MicrowavepropWeb.AlgoLive do
   @moduledoc false
   use MicrowavepropWeb, :live_view
 
-  @algo_path Path.join(:code.priv_dir(:microwaveprop), "../algo.md")
+  @external_resource "algo.md"
+  @algo_html "algo.md" |> File.read!() |> Earmark.as_html!()
 
   @impl true
   def mount(_params, _session, socket) do
-    content =
-      @algo_path
-      |> File.read!()
-      |> Earmark.as_html!()
-
-    {:ok, assign(socket, page_title: "Algorithm", content: content)}
+    {:ok, assign(socket, page_title: "Algorithm", content: @algo_html)}
   end
 
   @impl true