Ok so I managed to sort of get it working.
I had to put the following in my root composer.json file:
"psr-4": {
"App\\": "app/",
"Bobbybouwmann\\Entry\\": "packages/bobbybouwmann/entry/src/Entry"
}
And then in my command line I ran the following:
composer dump-autoload -o
And it worked.
However as soon as I do composer dump-autoload without using -o.
So:
composer dump-autoload
Then it breaks again.
Why would optimizing the composer dump-autoload make it work over not optimizing it?