feat(pastes): use rustler for highlight NIF

Signed-off-by: SphericalKat <amolele@gmail.com>

lib/ketbin/utils/syntax.ex

@@ -2,5 +2,9 @@ defmodule Ketbin.Utils.Syntax do
   use Rustler, otp_app: :ketbin, crate: "ketbin_utils_syntax"
 
   # When your NIF is loaded, it will override this function.
-  def add(_a, _b), do: :erlang.nif_error(:nif_not_loaded)
+  def add(_a, _b), do: error()
+
+  def highlight_text(_text, _lang), do: error()
+
+  defp error(), do: :erlang.nif_error(:nif_not_loaded)
 end

lib/ketbin_web/templates/page/show.html.eex

@@ -8,5 +8,5 @@
 		</a>
 		<% end %>
 	</div>
-	<code class="break-word px-6 py-4 h-full w-full nomarkdown overflow-y-auto"><%= @paste.content %></code>
+	<code class="break-word px-6 py-4 h-full w-full nomarkdown overflow-y-auto"><%= raw Ketbin.Utils.Syntax.highlight_text(@paste.content, "rs") %></code>
 </div>