Environment variables to control the app

• WIDTH the width of the offscreen canvas
• HEIGHT the height of the offscreen canvas
• PORT controls the port of the http server (3002 is default)

On a VPS without GPU lavapipe should be used:

VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/lvp_icd.x86_64.json

If DISCORD_TOKEN & GUILD_ID are present discord support will be activated.