docs(readme): write the detailed description

README.md

@@ -1,13 +1,58 @@
-# [WIP] monorepo for Hono middleware
+# monorepo for Hono third-party middleware
 
-This repository is monorepo for middleware of Hono.
+This repository is monorepo for third-party middleware of Hono.
+We develop middleware in this repository and manage the issues and pull requests.
 
-**Still working in progress**.
+## What is third-party middleware?
 
-## Author
+Hono has three types of middleware.
 
-Yusuke Wada
+1. Custom middleware - Created by users themselves.
+2. Built-in middleware - Included in the Hono core package. It does not depend on any other external libraries.
+3. Third-party middleware - Created outside of the core package. It can depend on the external libraries.
 
-## License
+Third-party middleware is maintained in this `github.com/honojs/middleware` repository and published to npm in the `@honojs` namespace. For example, a third-party middleware called hello is hosted at `github.com/honojs/middleware/packages/hello` and distributed under the name `@honojs/hello`.
+You can install with the following command.
 
-MIT
+```
+npm install @honojs/hello
+```
+
+For Deno, the modules, we do not publish them on `deno.land/x`, but distribute them via CDNs such as Skypack and esm.sh. We will also use the `npm:` that will be introduced in the Deno itself in the future.
+
+```ts
+import { hello } from 'npm:@honojs/hello'
+```
+
+## How to contribute
+
+Anyone can propose third-party Middleware.
+The Hono maintainers and other contributors will discuss to whether we accept the middleware or not.
+If it's OK, it will be maintained in this repository.
+Basically, the proposer maintains it.
+
+The specific flow is as follows
+
+1. Clone this repository
+2. Write your middleware. Refer to [hello Middleware](https://github.com/honojs/middleware/tree/main/packages/hello).
+3. Create the pull request.
+
+We use [changesets](https://github.com/changesets/changesets) to manage releases and CHANGELOG.
+Run the following command at the top level to describe any changes.
+
+```
+yarn changeset
+```
+
+When merged into main, a pull request for release is created.
+The Hono maintainers will merge it to release the package at the appropriate time.
+
+## Migration from the repository
+
+If possible, please migrate middleware previously managed in an independent repository to this one.
+Create the pull request with the content in the middleware repository. Perhaps `git-subtree` might be useful.
+
+## Author & License
+
+The Author of this repository is Yusuke Wada <<https://github.com/yusukebe>>. However, the code under the `packges/*` is in each Middleware author.
+Basically, distribute under the MIT license.