Improve page structure

Author: Granjow

index.md

@@ -1,21 +1,33 @@
-FreeOpcUa is a project to implement an open-source (LGPL) OPC-UA stack and associated tools. 
+FreeOpcUa is a project to implement an open-source (LGPL) OPC UA stack and associated tools.
 
-Currently FreeOpcUa is composed of
-* A LGPL C++ library to develop server and client OPC-UA applications. Python bindings can be found in the opcua-python repository. https://github.com/FreeOpcUa/freeopcua
-* A LGPL Python OPC-UA Python Client and Server library, written entirely in python, available at: https://github.com/FreeOpcUa/python-opcua (install using pip install opcua)
-* A GUI client https://github.com/FreeOpcUa/opcua-client-gui (install using pip install freeopcua-client)
-* Command line tools installed with freeopcua-python https://github.com/FreeOpcUa/python-opcua/tree/master/tools 
-* A GUI to create OPC UA nodes and save them to xml https://github.com/FreeOpcUa/opcua-modeler
+Currently FreeOpcUa is composed of:
 
-* Mailing list: https://groups.google.com/forum/#!forum/freeopcua
-* Source code: https://github.com/FreeOpcUa
+* An LGPL **[C++ library][c-lib]** to develop server and client OPC UA applications.
+  Python bindings can be found in the opcua-python repository on GitHub.
+* An LGPL OPC UA **[Client and Server library in Python][py-lib]**  
+  Install with `pip install opcua`
+* A **[GUI client][gui]** and a **[GUI modeler][modeler]** to create OPC UA nodes and save them to xml   
+  Install the client using `pip install freeopcua-client`
+* **[Command line tools][tools]**  
+  Install with `pip install freeopcua-python` or `apt install python-opcua-tools` (Ubuntu 18.04 and newer)
 
-Screenshot of client GUI:
+[c-lib]: https://github.com/FreeOpcUa/freeopcua
+[py-lib]: https://github.com/FreeOpcUa/python-opcua
+[gui]: https://github.com/FreeOpcUa/opcua-client-gui
+[modeler]: https://github.com/FreeOpcUa/opcua-modeler
+[tools]: https://github.com/FreeOpcUa/python-opcua/tree/master/tools
 
+## Links
 
-![Screenshot](/screenshot.png?raw=true "Screenshot")
+* Mailing list: [https://groups.google.com/forum/#!forum/freeopcua](https://groups.google.com/forum/#!forum/freeopcua)
+* Source code: [https://github.com/FreeOpcUa](https://github.com/FreeOpcUa)
+
+## Screenshots
 
-Screenshot of modeler:
+### Client GUI
+
+![Screenshot](/screenshot.png?raw=true "Screenshot")
 
+### Modeler
 
 ![Screenshot](/screenshot-modeler.png?raw=true "Screenshot")