chore: add headers to response

Author: Aetherinox

src/index.js

@@ -289,7 +289,14 @@ async function handleRequest(req, env, ctx) {
 
     let res = new Response(JSON.stringify({ Status, Comment }), {
         headers: {
-        "Content-Type": "application/json"
+            'content-type': types.json,
+            'Access-Control-Allow-Methods': 'GET, HEAD, OPTIONS, POST',
+            'Access-Control-Allow-Headers': 'Content-Type',
+            'Access-Control-Allow-Origin': '*',
+            'Access-Control-Max-Age': '3600',
+            'server': 'DNS-over-HTTPS/2.3.7 (+https://github.com/aetherinox/dns-over-https-worker)',
+            'x-powered-by': 'DNS-over-HTTPS/2.3.7 (+https://github.com/aetherinox/dns-over-https-worker)',
+            'Vary': 'Accept',
         },
     });