Download depended package after installing module

Question

I am developing QrCode Extension in Magento2 which is depended [bacon-qr-code] library so I need to download [bacon-qr-code] library using composer.In Magento2 in root composer.json if I add the

  "require": {
    "magento/module-offline-shipping-sample-data": "100.1.*",
    "bacon/bacon-qr-code": "1.0.1.*"
},

Then it download in vendor folder and I am able to use but what if I provide my Extension to anyone, will he add this line to its main root composer.json file ?? Or download the package manually I am little confuse please suggest me.I followed this link but did not get clear suggestion.

1:- Magento2: How to include third pary module through composer.json in custom module

:-My Module composer.json file

    {
    "name": "Ktpl/Relatedprod",
    "description": "N/A",
    "require": {
        "php": "~5.6.0|7.0.2|~7.0.6",
        "magento/magento-composer-installer": "*",
         "bacon/bacon-qr-code": "1.0.1.*"
    },
    "type": "magento2-module",
    "version": "2.0.0",
    "license": ["GPL-3.0"],
    "autoload": {
        "files": ["registration.php"],
        "psr-4": {
            "Ktpl\\Relatedprod\\": ""
        }
    }
}

Answer 1

You have to given documentation for this module,

You can set readme.txt file in your module installation.

This is the code for getting Bacon Qr Code in your project.

composer require mpyw/co:^1.5

Just set hint before installation. so after running above command automatically create folder in magento directory.

If you provide extension with composer command to install your module, add require code in composer.json file so when composer update its automatically getting Bacond qr code.