add desktop file and icon and have that installed, menu as popover, deb package cleanup

README.md

@@ -1,25 +1,34 @@
 # FLIR-GTK
 
 GTK+ application for FLIR ONE USB thermal camera based on flir-v4l:
-  Copyright (C) 2015-2016 Thomas <tomas123 @ EEVblog Electronics Community Forum>
-  https://github.com/fnoop/flirone-v4l2
+>  Copyright (C) 2015-2016 Thomas <tomas123 @ EEVblog Electronics Community Forum>
+
+[https://github.com/fnoop/flirone-v4l2](https://github.com/fnoop/flirone-v4l2)
 
 
-== depdendencies ==
+## depdendencies
+```
 GTK+-3.0
 Cairo
 libusb-1.0
 libjpeg
 libcjson
-
+```
 This should install everything under Debian and derivatives:
 
 apt install libgtk-3-dev libjpeg-dev libusb-1.0-0-dev libcjson-dev
 
-== building ==
-Makefile relies on pkg-config, if setup correctly simply running 'make'
-should build the application.
+## building
+If you check out the code from git you first need to clone submodule cairo-jpeg:
+    git submodule init
+    git submodule update
 
-== libusb & udev ==
-cp 77-flirone-lusb.rules /lib/udev/rules.d/
-udevadm control --reload-rules
+Makefile relies on pkg-config, if setup correctly simply running 'make'
+should build the application which can be run from the source directory,
+'make deb' builds a Debian package (to the parent directory)
+
+## libusb & udev
+For access rights of the application to the USB device:
+
+    cp 77-flirone-lusb.rules /lib/udev/rules.d/
+    udevadm control --reload-rules