remove workshop announcement from README

Author: bpostlethwaite

README.md

@@ -4,12 +4,6 @@
 
 ***
 
-#### 📢 Announcement!
-#### Seats are still available for a 2 day, Plotly.js & React master class in NYC, November 18-19.
-#### [Registration here](https://plotcon.plot.ly/workshops) 🎨 📈 🗽
-
-***
-
 ## Contents
 - [Installation](#installation)
 - [Quick start](#quick-start)