Add 'prerelease' to the alpha warning on the landing page.
Add 'prerelease' to the alpha warning on the landing page.

charnpreetsingh185/jupyterlab,eskirk/jupyterlab,jupyter/jupyterlab,jupyter/jupyterlab,charnpreetsingh185/jupyterlab,jupyter/jupyterlab,charnpreetsingh185/jupyterlab,eskirk/jupyterlab,TypeFox/jupyterlab,TypeFox/jupyterlab,eskirk/jupyterlab,eskirk/jupyterlab,charnpreetsingh185/jupyterlab,charnpreetsingh185/jupyterlab,jupyter/jupyterlab,TypeFox/jupyterlab,eskirk/jupyterlab,TypeFox/jupyterlab,TypeFox/jupyterlab,jupyter/jupyterlab