feat(cli): add guidance to use CLI with submodules (#626)

* Add a --help or -h command to the CLI

* Add a few more CLI examples to README

* Use `$` instead of `>` to indicate terminal commands

README.md

@@ -33,7 +33,10 @@ considered acknowledgement and acceptance of these terms and of its license.
 **CLI** (Command line interface)
 
 ```bash
+$ npx yahoo-finance2 --help
 $ npx yahoo-finance2 search AAPL
+$ npx yahoo-finance2 quoteSummary AAPL
+$ npx yahoo-finance2 quoteSummary AAPL '{"modules":["assetProfile", "secFilings"]}'
 
 # or install it
 $ npm install -g yahoo-finance2

bin/yahoo-finance.js

@@ -9,6 +9,23 @@ const script = process.argv[1];
 const moduleName = process.argv[2];
 const argsAsStrings = process.argv.slice(3);
 
+if (moduleName === "--help" || moduleName === "-h") {
+  console.log();
+  console.log("Usage: yahoo-finance.js <module> <args>");
+  console.log();
+  console.log("Get a quote for AAPL:");
+  console.log("$ yahoo-finance.js quoteSummary AAPL");
+  console.log();
+  console.log("Run the quoteSummary module with two submodules:");
+  console.log(
+    '$ yahoo-finance.js quoteSummary AAPL \'{"modules":["assetProfile", "secFilings"]}\''
+  );
+  console.log();
+  console.log("Available modules:");
+  console.log(moduleNames.join(", "));
+  process.exit();
+}
+
 if (!moduleNames.includes(moduleName)) {
   console.log("No such module: " + moduleName);
   console.log("Available modules: " + moduleNames.join(", "));