Use well-known labels in project URLs following PEP753

[seisman]

Description of proposed changes

Use human-readable labels for project URLs. See the sidebar of https://pypi.org/project/matplotlib/ for how the new URLs will look like:

References:

• https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#urls
• https://packaging.python.org/en/latest/specifications/well-known-project-urls/#well-known-labels
• https://docs.pypi.org/project_metadata/#general-url
• https://peps.python.org/pep-0753/ [TL;DR]

[yvonnefroehlich]

A bit off topic: While looking at the PyGMT PyPi website, I am wondering what all means for the Meta entry "Provides-Extra":

[seisman]

It means people can use pip install pygmt[all] to install pygmt and its optional dependencies. It's from

pygmt/pyproject.toml

Lines 41 to 48 in 4b9314a

	[project.optional-dependencies]
	all = [
	"contextily",
	"geopandas",
	"IPython", # 'ipython' is not the correct module name.
	"pyarrow",
	"rioxarray",
	]