Add pip install to readme

Author: gyfis

README.md

@@ -13,3 +13,15 @@ This repository contains the [Logtail](https://logtail.com) Python library, turn
 * Support for structured logging and events.
 * Automatically captures useful context.
 * Performant, light weight, with a thoughtful design.
+
+---
+
+### Installation
+
+Install the Logtail client library from PyPI as you would with any other package:
+
+```
+pip install logtail-python
+```
+
+Make sure you install the `logtail-python` package and not a different package with the `logtail` keyword in the package name from a different author.