Add debian installation instructions to README.md

Author: watson

README.md

@@ -16,13 +16,20 @@ This software also requires that you have
 system. In turn librtlsdr requires [libusb](http://libusb.info/).
 
 You can install librtlsdr with most package managers which will ensure
-you have the right dependencies. To install using Homebrew on macOS,
-simply run:
+you have the right dependencies.
+
+Homebrew (macOS):
 
 ```
 brew install librtlsdr
 ```
 
+Debian based Linux distros:
+
+```
+apt-get install librtlsdr-dev
+```
+
 ## Usage
 
 ```