feat: Add manual instructions to README

[fabricionaweb]

Svelte docs suggest us to use dotenv dependency to load from the .env file https://kit.svelte.dev/docs/adapter-node#environment-variables

I followed the steps similar to the Dockerfile, I just mention the v18.14.0 because it is the first version to comes with NPM 9 (which uses the lock-file 3) so that may keep things more consistent and error prone.

I also splitted the Docker instructions in two, as I think not everyone needs compose.

This may closes #45 but yet people needs to built their own daemon... Maybe another MR I can add some daemon examples like Systemd and OpenRC

[aleksilassila]

Lmk when this is ready and I'll review and merge 👍

[fabricionaweb]

Its ready... the --restart on docker cli is optional, idk if worth to present it but I left to be similar to compose... there is also the -d to run in background that maybe can be added to the cli command, not sure but you decided what is better :D