Enhance cli about info (#13)

* feat(cli): 增强命令行工具版本信息和描述

更新了 CLI 参数解析器的配置，添加了详细的版本信息和工具描述，使用环境变量获取包版本，并提供了更完整的关于信息。

Signed-off-by: longjin <longjin@DragonOS.org>

* chore: 更新版本号至0.2.1

Signed-off-by: longjin <longjin@DragonOS.org>

---------

Signed-off-by: longjin <longjin@DragonOS.org>

Author: fslongjin

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "fastcommit"
-version = "0.2.0"
+version = "0.2.1"
 description = "AI-based command line tool to quickly generate standardized commit messages."
 edition = "2021"
 authors = ["longjin <fslongjin@vip.qq.com>"]

Cargo.toml

@@ -10,7 +10,7 @@ You can install `fastcommit` using the following method:
 
 ```bash
 # Install using cargo
-cargo install --git  https://github.com/fslongjin/fastcommit --tag v0.2.0
+cargo install --git  https://github.com/fslongjin/fastcommit --tag v0.2.1
 ```
 
 ## Usage

README.md

@@ -8,7 +8,7 @@
 
 ```bash
 # 使用 cargo 安装
-cargo install --git  https://github.com/fslongjin/fastcommit --tag v0.2.0
+cargo install --git  https://github.com/fslongjin/fastcommit --tag v0.2.1
 ```
 
 ## 使用

README_CN.md

@@ -3,7 +3,13 @@ use clap::Parser;
 use crate::config::{CommitLanguage, Verbosity};
 
 #[derive(Parser, Debug)]
-#[clap(version, about)]
+#[clap(
+    version = env!("CARGO_PKG_VERSION"),
+    about = concat!(
+        "AI-based command line tool to quickly generate standardized commit messages.\n\n",
+        "Version: ", env!("CARGO_PKG_VERSION")
+    )
+)]
 pub struct Args {
     #[clap(short, long, help = "Path to the file containing the diff to analyze")]
     pub diff_file: Option<String>,