Split code into multiple files

domains.go

@@ -0,0 +1,11 @@
+package main
+
+import "github.com/valyala/fasthttp"
+
+// getTargetFromDNS searches for CNAME entries on the request domain, optionally with a "www." prefix, and checks if
+// the domain is included in the repository's "domains.txt" file. If everything is fine, it returns the target data.
+func getTargetFromDNS(ctx *fasthttp.RequestCtx) (targetOwner, targetRepo, targetBranch, targetPath string) {
+	// TODO: read CNAME record for host and "www.{host}" to get those values
+	// TODO: check domains.txt
+	return
+}