docs: update README.md

Author: Thaumy

README.md

@@ -2,3 +2,70 @@
 
 [![Build / Release](https://github.com/cnblogs/cli/actions/workflows/build-release.yml/badge.svg)](https://github.com/cnblogs/cli/actions/workflows/build-release.yml)
 [![Build / Development](https://github.com/cnblogs/cli/actions/workflows/build-dev.yml/badge.svg)](https://github.com/cnblogs/cli/actions/workflows/build-dev.yml)
+
+Access cnblogs form CLI.
+
+## Usage
+
+To use `cnb` directly, register it to your environment variables is required.
+
+### Login
+
+You need to get your PAT from [https://account.cnblogs.com/settings/tokens](https://account.cnblogs.com/settings/tokens) to use this tool.
+
+Then run `cnb user --login 'YOUR_PAT_HERE'`. This will save your PAT to `~/.cnbrc`.
+
+If you want to logout, run `cnb user --logout` or just remove `~/.cnbrc`.
+
+### Examples
+
+After login, it's time to enjoy cnblogs.
+
+Here are some simple examples:
+
+```shell
+# Check your post list
+cnb post --list
+# Check your post 
+cnb --id 114514 post --show
+# Create and publish post 
+cnb post create --title 'Hello' --body 'world!' --publish
+# Change your post body
+cnb --id 114514 post update --body 'niconiconiconi'
+
+# Show ing list
+cnb ing --list
+# Publish ing 
+cnb ing --pub 'Hello world!'
+# Comment to ing 
+cnb --id 114514 ing --comment 'Awesome!'
+
+# Check your user infomation
+cnb user --info
+```
+
+For more information, try `cnb --help`.
+
+## Installation
+
+### Build
+
+This tool needs nightly toolchains(1.74.0+) to build.
+
+```shell
+git clone --depth 1 https://github.com/cnblogs/cli.git
+cd cli
+cargo build -r
+```
+
+Or get binaries from [CI](https://github.com/cnblogs/cli/actions) artifacts.
+
+### License
+
+[MIT](https://raw.githubusercontent.com/cnblogs/cli/main/LICENSE)
+
+### Feedback
+
+We’d love to hear your thoughts on this project. Feel free to drop us a note!
+
+[Issues](https://github.com/cnblogs/cli/issues)