docs: remove lgtm.com badge

Author: kyranet

README.md

@@ -8,7 +8,6 @@
 
 [![npm](https://img.shields.io/npm/v/canvas-constructor.svg?maxAge=3600)](https://www.npmjs.com/package/canvas-constructor)
 [![npm](https://img.shields.io/npm/dt/canvas-constructor.svg?maxAge=3600)](https://www.npmjs.com/package/canvas-constructor)
-[![Total alerts](https://img.shields.io/lgtm/alerts/g/kyranet/canvas-constructor.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/kyranet/canvas-constructor/alerts/)
 [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/kyranet/canvas-constructor/master/LICENSE)
 
 [![Support Server](https://discord.com/api/guilds/437335547711848458/embed.png?style=banner2)](https://discord.gg/taNgb9d)