Webhook + Heroku changes + Optimisation images loader

This PR adds a WebHook used to queue memes

Changelog

Fixed:

• Instead of erroring "file not found" shows a warning if no meme is found, before attempting to read empty path

Added:

• New WebHook (optional) to queue messages
• Basic Authentication for WebHook
• Basic documentation on how to use it
• Env variables for Heroku
• Git LFS build pack for Heroku (apps)

Changed:

• Log format and data on some functions to avoid spamming

Checklist

Ensure that before making this PR you have:

• Read the contributing guidelines
• Agreed with the LICENSE
• Run go fmt ./...
• Run go mod tidy