Adding compiled css to .gitignore.
Adding compiled css to .gitignore.

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