style: code maid is here!

refactored the project significantly to reduce the single-file monolith

util/util.go

@@ -0,0 +1,10 @@
+package util
+
+import (
+	"crypto/sha1"
+	"fmt"
+)
+
+func Hash(s string) string {
+	return fmt.Sprintf("%x", sha1.Sum([]byte(s)))
+}