serve https if there is ca.crt and ca.key

.gitignore

@@ -9,3 +9,5 @@
 _fresh/
 
 *.kate-swp
+ca.crt
+ca.key

main.ts

@@ -9,4 +9,18 @@ import "$std/dotenv/load.ts";
 import { start } from "$fresh/server.ts";
 import manifest from "./fresh.gen.ts";
 
-await start(manifest);
+const cert_file = 'ca.crt';
+const key_file = 'ca.key';
+
+const cert = await Deno.readTextFile(cert_file).catch(() => '');
+const key = await Deno.readTextFile(key_file).catch(() => '');
+
+if (cert !== '' && key !== '')
+    await start(manifest, {
+        server: {
+            cert: cert,
+            key: key
+        }
+    });
+else
+    await start(manifest);