Changed tl; dr to summary (pyscript#216)

Author: goodylili

README.md

@@ -2,7 +2,7 @@
 
 ## What is PyScript
 
-### tl;dr
+### Summary
 PyScript is a Pythonic alternative to Scratch, JSFiddle or other "easy to use" programming frameworks, making the web a friendly, hackable, place where anyone can author interesting and interactive applications.
 
 To get started see [GETTING-STARTED](GETTING-STARTED.md).