How to connect JS library to Chrome Extensions?

Question

JavaScript

The manifest file itself:

{
"name": "CHANGE THIS",
"version": "0.0.1",
"manifest_version": 2,
"description": "This extension was created with the awesome extensionizr.io",
"homepage_url": " extensionizr. com ",
"default_locale": "en",
"content_scripts": [
{
"matches": [" vk.com/* "],
"js": [
"src/inject/inject.js",
"src/jqury .min.js"
]
}
]
}

And I call from inject.js In the console it is written that

$('#side_bar').append('!!!!!!!!!!!!!!!!!!');<br>

Uncaught ReferenceError: $is not defined

How to be?