add guide on how to install qmenu

A short guide on how to install https://github.com/sine3o14nnae/qmenu in dom0. 
The installation itself has serious security implications but some users could benifit from these tools.

docs/configuration/qmenu.md

@@ -0,0 +1,85 @@
+Manage Qubes via dmenu
+==============================
+
+qmenu
+-----
+
+[qmenu](https://github.com/sine3o14nnae/qmenu/) is a collection of tools that utilize
+[dmenu](https://tools.suckless.org/dmenu/), a dynamic menu for X, to provide you with a drop down menu for Qubes specific tasks.
+
+When configured to execute these tools via hotkeys, you are able to list, start and stop your qubes, attach and detach your connected devices,
+adjust your qube preferences, firewall rules, per-qube keyboard layouts, launch applications and more, very quickly with only the keyboard.
+
+List of qmenu tools:
+
+- qmenu-al - Launch domU applications.
+
+- qmenu-dm - List and manage your connected devices.
+
+- qmenu-vm - List, manage and configure your qubes.
+
+Warning
+-------
+
+qmenu is **not** included in the Qubes dom0 repositories. This page will show you how to install qmenu by cloning its repository
+to a disposable qube and [copying its contents to dom0](https://www.qubes-os.org/doc/copy-from-dom0/#copying-to-dom0).
+**However, this way of installing software in dom0 is not advised and can compromise the security of your system!**
+
+**Furthermore, qmenu is unreviewed third party software and is in no way endorsed by the Qubes team. You have to trust its maintainers
+to not act maliciously and to protect it from malicious and unsafe contributions. Keep in mind that you are
+installing these tools in _dom0_, so judge accordingly.**
+
+Installation
+------------
+
+- Install dmenu:
+
+       [user@dom0]$ sudo qubes-dom0-update dmenu
+
+- Start a disposable qube that is able to connect to the internet. **Do not use this qube for anything else!**
+Then inside this qube; clone the qmenu repository with git:
+
+       [user@dispXXXX ~]$ git clone https://github.com/sine3o14nnae/qmenu/
+
+- Import the authors public key:
+
+       [user@dispXXXX ~]$ gpg2 --keyserver pool.sks-keyservers.net --recv-keys 0xCBE6 0BC2 811F FE14 333F EE05 3435 0BCA 3DDE 9AD9
+
+- Check the validity of the signed commit:
+
+       [user@dispXXXX ~/qmenu/]$ git show --show-signature
+
+- Finally, decide what qmenu tools you want to use, replace 'XX' accordingly, then copy them to dom0, place them
+inside your path and change their mode bits.
+
+       [user@dom0 ~]$ qvm-run --pass-io dispXXXX 'cat /home/user/qmenu/qmenu-XX' > /tmp/qmenu-XX
+
+       [user@dom0 ~]$ sudo cp /tmp/qmenu-XX /usr/bin/
+
+       [user@dom0 ~]$ sudo chmod 755 /usr/bin/qmenu-XX
+
+- _Optionally_, copy the default config file:
+
+       [user@dom0 ~]$ qvm-run --pass-io dispXXXX 'cat /home/user/qmenu/qmenu.conf' > /home/user/.config/qmenu.conf
+
+Customization
+-------------
+
+### qmenu ###
+
+The colors that correspond to the qube label can be adjusted by creating a text file called
+`qmenu.conf` in `/home/user/.config/` with the following contents:
+
+~~~
+[LABEL 1]=#[HEX TRIPLET]
+[LABEL 2]=#[HEX TRIPLET]
+...
+[LABEL 8]=#[HEX TRIPLET]
+~~~    
+
+### dmenu ###
+
+In order to customize and configure dmenu, instead of downloading it from the repositories,
+you have to get it from [suckless](https://tools.suckless.org/dmenu/patches/), compile it yourself
+and [copy it to dom0](https://www.qubes-os.org/doc/copy-from-dom0/#copying-to-dom0).
+**However, this way of installing software in dom0 is not advised and can compromise the security of your system!**