docs: remove survey now that its closed

README.md

@@ -8,10 +8,6 @@
 
 A library that generates an interactive radar, inspired by [thoughtworks.com/radar](http://thoughtworks.com/radar).
 
-## Technology Radar Survey
-
-Take our short survey to help make the Technology Radar even better: https://www.thoughtworks.com/radar/survey.
-
 ## Demo
 
 You can see this in action at https://radar.thoughtworks.com. If you plug in [this data](https://docs.google.com/spreadsheets/d/1GBX3-jzlGkiKpYHF9RvVtu6GxSrco5OYTBv9YsOTXVg/edit#gid=0) you'll see [this visualization](https://radar.thoughtworks.com/?sheetId=https%3A%2F%2Fdocs.google.com%2Fspreadsheets%2Fd%2F1GBX3-jzlGkiKpYHF9RvVtu6GxSrco5OYTBv9YsOTXVg%2Fedit%23gid%3D0).