Update PyPI author and project links

The author and project links shown on the [Visdom PyPI page](https://pypi.org/project/visdom/) are outdated. They currently refer to the original Facebook repository and former authors.

Update the package metadata in setup.py:

author="FOSSASIA",
author_email="[email protected]",
url="https://visdom.dev",
project_urls={
    "Homepage": "https://visdom.dev",
    "Source": "https://github.com/fossasia/visdom",
    "Issues": "https://github.com/fossasia/visdom/issues",
    "Releases": "https://github.com/fossasia/visdom/releases",
},

Acceptance criteria:

• PyPI lists FOSSASIA as the author.
• The author email is [email protected].
• The homepage points to https://visdom.dev.
• Source, issue tracker, and release links point to the FOSSASIA repository.
• The updated metadata is included in the next PyPI release.

Existing PyPI release metadata cannot be changed retroactively, so the changes will become visible on the main project page after publishing the next version.