Added distribs_install.md which describes what to setup/install when creating...

Added distribs_install.md which describes what to setup/install when creating base images for various linux distributions.

tools/distribs_install.md

+# Common to all distribs
+
+- username: `nexus`
+- password: `nexus`
+- if root, password: `nexus`
+- hostname: `nexus-pc`
+- login without password if selectable (autologin)
+
+# Ubuntu/Xubuntu
+
+Images: `ubuntu-22.04-desktop-amd64.iso` and `xubuntu-22.04-desktop-amd64.iso`
+
+```
+sudo -s
+apt-get update && apt-get upgrade -y
+apt-get install -y qemu-guest-agent vim tree qalc build-essential net-tools
+snap install codium --classic
+apt-get remove --purge -y thunderbird
+apt autoremove && apt autoclean
+fstrim -av
+systemctl enable fstrim.timer && sudo systemctl start fstrim.timer
+```
+
+# Fedora
+
+Image: `Fedora-Workstation-Live-x86_64-36-1.5.iso`
+
+```
+sudo -s
+dnf update && sudo dnf upgrade
+dnf install vim tree qalc snapd
+ln -s /var/lib/snapd/snap /snap
+snap install codium --classic
+fstrim -av
+systemctl enable fstrim.timer && systemctl start fstrim.timer
+```
+
+# Debian
+
+Image: `debian-11.4.0-amd64-DVD-1.iso` with xfce desktop.
+
+Skip the grub menu, otherwise it takes forever: change `/etc/default/grub` with:
+```
+GRUB_TIMEOUT=0
+```
+
+Update grub with:
+```
+update-grub && update-grub2
+```
+
+Setup autologin by adding the following to `/etc/lightdm/lightdm.conf` under `[Seat:*]`:
+```
+autologin-user=nexus
+autologin-user-timeout=0
+```
+
+Add sources by adding the following to `/etc/apt/sources.list`:
+```
+deb http://deb.debian.org/debian bullseye main contrib non-free
+deb-src http://deb.debian.org/debian bullseye main contrib non-free
+deb http://deb.debian.org/debian-security bullseye/updates main contrib non-free
+deb-src http://deb.debian.org/debian-security bullseye/updates main contrib non-free
+deb http://deb.debian.org/debian bullseye-updates main contrib non-free
+deb-src http://deb.debian.org/debian bullseye-updates main contrib non-free
+deb http://deb.debian.org/debian bullseye-backports main contrib non-free
+deb-src http://deb.debian.org/debian bullseye-backports main contrib non-free
+```
+
+```
+su -
+apt-get update && apt-get upgrade -y
+apt-get install -y qemu-guest-agent vim tree qalc build-essential net-tools snapd
+snap install core
+systemctl restart snapd && systemctl enable snapd
+snap install codium --classic
+apt autoremove && apt autoclean
+fstrim -av
+systemctl enable fstrim.timer && systemctl start fstrim.timer
+```
+
+# Manjaro
+
+Image: `manjaro-xfce-21.3.6-220729-linux515.iso`
+
+```
+sudo -s
+pamac update && pamac --no-confirm upgrade
+pamac install --no-confirm code vim tree qalculate-gtk net-tools
+fstrim -av
+systemctl enable fstrim.timer && systemctl start fstrim.timer
+```