fix!(markdown): prevent html injection

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

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

@@ -9,7 +9,7 @@
 		<% end %>
 	</div>
 	<%= if @extension == "md" do%>
-		<div class="break-word px-6 py-4 h-full w-full markdown overflow-y-auto"><%= raw Earmark.as_html!(@paste.content, escape: false, gfm_tables: true) %></div>
+		<div class="break-word px-6 py-4 h-full w-full markdown overflow-y-auto"><%= raw Earmark.as_html!(@paste.content, escape: true, gfm_tables: true) %></div>
 	<% else %>
 		<code class="break-word px-6 py-4 h-full w-full overflow-y-auto"><%= raw Ketbin.Utils.Syntax.highlight_text(@paste.content, @extension) |> HtmlSanitizeEx.html5 %></code>
 	<% end %>