Update README.md

Note bokeh>3.0 as unsupported

Author: Notou

README.md

@@ -11,7 +11,7 @@ The module was first developed as a part of Google Summer of Code 2017 by Kartik
 
 ## Dependency
 1. GNU Radio 3.9.5 or 3.10
-2. [Bokeh library above 2.3.1](https://docs.bokeh.org/en/2.3.2/) (earlier versions cause the waterfall display to crash)
+2. [Bokeh library above 2.3.1, and below 3.0](https://docs.bokeh.org/en/2.3.2/) (earlier versions cause the waterfall display to crash, and WidgetBox has been removed in later versions)
 3. NodeJS >= 14
 4. Netstat or ss to check open ports (optionnal)