Update compatibility note, binder example

Author: parente

README.md

@@ -9,7 +9,7 @@ Quickly open a file in JupyterLab by typing part of its name
 ## Compatibility
 
 - Python >=3.7.x
-- JupyterLab >=1.0,<2.0
+- JupyterLab >=2.0,<3.0
 - Jupyter Notebook >=6.0,<7.0
 - Notebook server configurations where notebook documents and other files reside on the local
   filesystem (which is the the notebook server default)

binder/requirements.txt

@@ -1,3 +1,3 @@
-jupyterlab>=1.0,<2.0a
+jupyterlab>=2.0,<3.0a
 jupyterlab-quickopen
 notebook>=6.0,<7.0a