Documentation improvements

[gdarko]

Documentation updates

• Add more details for docker
• Add more details for customer portal
• Add more details for developer contributions
• Add more details for translator contributions
• Improve manual installation steps (add .env file information)

[barnzilla]

I just recently migrated from Crater and want to thank everyone for their work on this fork!

When installing manually (Ubuntu 20, LAMP stack, PHP 8.2), I ran into an internal server error due to the fact that there was no .env file. I'm wondering if this should be included as a step within the manual installation documentation, i.e., copy .env.example to .env?

[gdarko]

Hey @barnzilla - That is a good idea. I will make sure we include it. (Just added to the above list). Thanks.

[barnzilla]

Thank you so much, @gdarko !

[CelicaXX]

Here it is stated that the default Database Host value is = invoiceshelf. This resulted in a failed connection. Checking ~/docker/invoiceshelf_mysql/conf/.env reveals that the correct value is invoiceshelf_db.