Add the JupyterLab trove classifiers

[jtpio]

Problem

The new trove classifiers for JupyterLab prebuilt extensions have just been added to PyPI. See the following issues and PRs for more context:

• Add jupyterlab trove classifiers pypa/trove-classifiers#72
• Add pypi classifiers jupyterlab/extension-cookiecutter-ts#174

This will help discover prebuilt JupyterLab extensions on PyPI. For example with this search request:

https://pypi.org/search/?c=Framework+%3A%3A+Jupyter+%3A%3A+JupyterLab+%3A%3A+Extensions+%3A%3A+Prebuilt

Proposed Solution

We should add them to the voila package too here:

voila/setup.py

Lines 111 to 120 in 56fe4cf

	classifiers=[
	"License :: OSI Approved :: BSD License",
	"Programming Language :: Python",
	"Programming Language :: Python :: 3",
	"Programming Language :: Python :: 3.6",
	"Programming Language :: Python :: 3.7",
	"Programming Language :: Python :: 3.8",
	"Programming Language :: Python :: 3.9",
	"Framework :: Jupyter",
	],

Framework :: Jupyter :: JupyterLab
Framework :: Jupyter :: JupyterLab :: 3
Framework :: Jupyter :: JupyterLab :: Extensions
Framework :: Jupyter :: JupyterLab :: Extensions :: Prebuilt

Additional context

[RhnSharma]

I would like to take this one.

[jtpio]

Thanks @RhnSharma, assigning to you!