modify README, add LICENSE

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Leafee98
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -17,3 +17,12 @@ Clone this repo, run follow command, and generated html will locationed at `dist
 yarn                # install dependencies
 yarn r --generate --config config-example.toml
 ```
+
+## Develop
+
+Clone this repo, run follow command, it will generate html and reload page realtime when you modify source code. Note this is implemented simply by polling a http path every second, so it will create a lot log under "Network" tag of browser's developer tools.
+
+```
+cp config-example.toml config.toml
+yarn watch
+```