README: document how to run multiple modules on command line [ci skip]

Author: CarterLi

README.md

@@ -93,7 +93,7 @@ See the Wiki: https://github.com/fastfetch-cli/fastfetch/wiki/Building
 
 * Run with default configuration: `fastfetch`
 * Run with [all supported modules](https://github.com/fastfetch-cli/fastfetch/wiki/Support+Status#available-modules) to find what interests you: `fastfetch -c all.jsonc`
-* View all data that fastfetch detects: `fastfetch -s <module> --format json`
+* View all data that fastfetch detects: `fastfetch -s <module1>[:<module2>][:<module3>] --format json`
 * Display help messages: `fastfetch --help`
 * Generate a config file based on command line arguments: `fastfetch --arg1 --arg2 --gen-config`