We had a few issues that were noted while going through an installation

process recently. There were a couple places where we specified the

wrong filesystem path to pip, and where we didn't document some

packages for Apache or apt build sources that may be needed if not

already installed on the system.
This change fixes up the documentation and adds the steps for installing

Apache + mod_wsgi, and enabling build sources. It also changes the order

of packages for the initial system package installation steps to help with

scanning and updating package entries.

Built the docs and read through them.
Ran the steps on an Ubuntu 22.04 system.