Merge pull request #6085 from JiaBao-do/update-readme

docs: Updated README to get started easily

Author: epage

README.md

@@ -12,6 +12,12 @@
 
 Dual-licensed under [Apache 2.0](LICENSE-APACHE) or [MIT](LICENSE-MIT).
 
+## Get Started
+
+```console
+$ cargo add clap
+```
+
 ## About
 
 Create your command-line parser, with all of the bells and whistles, declaratively or procedurally.