feat: add read/write

README.md

@@ -17,3 +17,18 @@ Mini-KMS runs local written by Rust
 ```shell
 ./local-mini-kms cli --offline-init
 ```
+
+Write value:
+```shell
+curl -X POST http://127.0.0.1:5567/write \
+     -H "Content-Type: application/json" \
+     -d '{"name":"test","value":{"value":"hello"}}'
+```
+
+Read value:
+```shell
+curl -X POST http://127.0.0.1:5567/read \
+     -H "Content-Type: application/json" \
+     -d '{"name":"test"}'
+```
+