doc: issues with installation (fixes #16)

Author: anthonyharrison

README.md

@@ -27,13 +27,15 @@ if you are using different versions of python. `virtualenv` is a tool for settin
 allows you to have all the dependencies for the tool set up in a single environment, or have different environments set
 up for testing using different versions of Python.
 
-### Issues with Windows Installation
+### Issues with Installation
 
-When running on Windows, if you get the following error
+If you get the following error
 
 `ImportError: failed to find libmagic.  Check your installation`
 
-This is because of a mismatch with the installation of the magic library. To resolve, please issue the following commands
+This is because of a mismatch with the installation of the magic library. To resolve, please issue the following commands depending on your environment
+
+#### Windows
 
 ```bash
 pip uninstall python-magic
@@ -43,6 +45,21 @@ pip install python-magic
 pip install python-magic-bin
 ```
 
+#### Linxu based system
+
+Install `libmagic` using a package manager, for example
+
+```bash
+apt install libmagic-dev
+```
+
+#### MacOS
+
+Install `libmagic` using a package manager, for example
+
+```bash
+brew install libmagic
+```
 
 ## Usage