README: add LibRaw version info, fix formatting

Author: mardy

README.md

@@ -4,36 +4,39 @@
 QtRaw
 =====
 
-Qt image plugin for loading raw files, via libraw. Once installed, it enables
-all Qt applications to load raw files produced by most digital cameras.
+Qt image plugin for loading raw files, via [LibRaw](https://www.libraw.org/).
+Once installed, it enables all Qt applications to load raw files produced by
+most digital cameras.
 
-The code is licensed udner the GPL v3 licence. If you need to distribute it
+The code is licensed under the GPL v3 licence. If you need to distribute it
 under a different license, please contact me at info@mardy.it
 
-INSTALL
-=======
 
-The QtRaw plugin depends on Qt and libraw. In order to build it, make sure you
-have the necessary development packages installed. Under Ubuntu, this can be
-achieved by running these commands:
+Installation
+------------
 
-  sudo apt-get install libraw-dev qtbase5-dev
+The QtRaw plugin depends on Qt and LibRaw (versions 0.15 till 0.19 are known to
+be working). In order to build it, make sure you have the necessary development
+packages installed. Under Ubuntu, this can be achieved by running these
+commands:
+
+    sudo apt-get install libraw-dev qtbase5-dev
 
 for building with Qt 5, or
 
-  sudo apt-get install libraw-dev libqt4-dev
+    sudo apt-get install libraw-dev libqt4-dev
 
 for building with Qt 4.
-Alternatively, you can find the libraw source code at
-http://www.libraw.org/download
+Alternatively, you can find the LibRaw source code at
+http://www.libraw.org/download and build it yourself.
 
 
 Once the dependencies are set up, the following commands will build and install
 the plugin into your system:
 
-  qmake
-  make
-  sudo make install
+    qmake
+    make
+    sudo make install
 
-If everything worked correctly, all Qt applications should be able to load and
-display raw camera files.
+If everything worked correctly, all Qt applications should now be able to load
+and display raw camera files.