更新 '#README.md'

#README.md

@@ -0,0 +1,13 @@
+# XOR Encrypt
+
+a simple xor encryption that encodes to base64 for url safe
+
+## Usage
+
+```go
+msg := "test"
+key := "key"
+enc := Encrypt(msg, key)
+dec, _ := Decrypt(enc, key)
+fmt.Printf("%s -> %s -> %s\n", msg, enc, dec)
+```