📝 Update doc to use npx (#55)

README.md

@@ -56,33 +56,22 @@ Example of `package.json` with good meta data:
 }
 ```
 
-## 📦 Install
+## 🚀 Usage
 
-With npm:
+Make sure you have [npx](https://www.npmjs.com/package/npx) installed (`npx` is shipped by default since npm `5.2.0`)
 
-```sh
-npm i -g readme-md-generator
-```
-
-With yarn:
+Just run the following command at the root of your project and answer questions:
 
 ```sh
-yarn global add readme-md-generator
+npx readme-md-generator
 ```
 
-## 🚀 Usage
-
-Just run the following command at the root of your project and answer questions:
+OR use default values for all questions (`-y, --yes`):
 
 ```sh
-readme
+npx readme-md-generator -y
 ```
 
-### Available options
-
-- `--version` Display `readme-md-generator` version number
-- `-y, --yes` Use default values for all questions
-
 ## 🤝 Contributing
 
 Contributions, issues and feature requests are welcome.<br />