readme: elaborate on user site installation

Author: jaxxzer

README.md

@@ -36,9 +36,11 @@ $ pip install --user bluerobotics-ping
 ```sh
 $ git clone https://github.com/bluerobotics/ping-python.git
 $ cd ping-python
-$ python setup.py install
+$ python setup.py install --user
 ```
 
+The library is ready to use: `import brping`. If you would like to use the command line [examples](/examples) or [tools](/tools) provided by this package, follow the notes in python's [installing to user site](https://packaging.python.org/tutorials/installing-packages/#installing-to-the-user-site) directions (eg `export PATH=PATH:~/.local/bin`).
+
 ## Quick Start
 
 The `bluerobotics-ping` package installs a `simplePingExample.py` script to get started. Place your device's file descriptor (eg. `/dev/ttyUSB0`, `COM1`) after the --device option.