update README

Signed-off-by: ふぁ <yuki@yuki0311.com>

CONTRIBUTING.md

@@ -0,0 +1,15 @@
+# CONTRIBUTING
+
+- `src` *.yaml files should be written according to the [v3.0/schema.json](https://raw.githubusercontent.com/OAI/OpenAPI-Specification/main/schemas/v3.0/schema.json)
+- `dist` Do not rewrite this file as it is an automatically generated OpenAPI file.
+- `dist` Do not include this in the pull request due to potential conflicts.
+
+I'm using openapi-generator with a dart-dio build.
+It is desirable to pass these tests.
+Untested pull requests are welcome, as Dart's development population is very small.
+<https://github.com/fa0311/twitter_openapi_dart/tree/main/twitter_openapi_dart/test>
+
+## Good first issues
+
+- Add a new endpoint
+- Add type to `type: object # todo`

README.md

@@ -20,8 +20,7 @@ Note that the license also inherits to the output.
 
 ## Contribute
 
-- `src` *.yaml files should be written according to the [v3.0/schema.json](https://raw.githubusercontent.com/OAI/OpenAPI-Specification/main/schemas/v3.0/schema.json)
+[CONTRIBUTING.md](./CONTRIBUTING.md)
-- `dist` Do not rewrite this file as it is an automatically generated OpenAPI file.
 
 ### build