Cheat sheet header adjustment

Brings the header of this cheat sheet inline with the website and pdf version.

Author: MattCSmith

README.md

@@ -1,6 +1,8 @@
 Python ZTM Cheatsheet 💻🚀
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+We created this Python 3 Cheat Sheet initially for students of [Complete Python Developer in 2020: Zero to Mastery](https://academy.zerotomastery.io/p/complete-python-developer-zero-to-mastery) but we're now sharing it with any Python beginners to help them learn and remember common Python syntax and with intermediate and advanced Python developers as a handy reference. If you'd like to download a PDF version of this Python Cheat Sheet, you can get it [here](https://zerotomastery.io/courses/python/cheatsheet/?utm_source=github&utm_medium=ztm-python-cheat-sheet)!
+
 Contents
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 **Python Types:** **[`Numbers`](#numbers)__,__[`Strings`](#strings)__,__[`Boolean`](#boolean)__,__[`Lists`](#lists)__,__[`Dictionaries`](#dictionaries)__,__ [`Tuples`](#tuples)__,__[`Sets`](#sets)__,__[`None`](#none)**