Add Mars dataset

[willschlitzer]

This pull request adds a function to the dataset samples for the mars370d.txt file used in the sphinterpolate example.

Fixes #

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If adding new functionality, add an example to docstrings or tutorials.

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• /format: automatically format and lint the code
• /test-gmt-dev: run full tests on the latest GMT development version

[weiji14]

Just one minor docstring suggested change to apply (you'll need to resolve the merge conflict with load_hotspot first though).

Catching up on the discussion at #1436 (comment), if we're moving to follow the seaborn.load_dataset model, then this PR would need substantial changes. Do you want to do the refactoring here or separately?

[willschlitzer]

Just one minor docstring suggested change to apply (you'll need to resolve the merge conflict with load_hotspot first though).

Catching up on the discussion at #1436 (comment), if we're moving to follow the seaborn.load_dataset model, then this PR would need substantial changes. Do you want to do the refactoring here or separately?

My thought is to handle it with a separate PR. While I don't want to duplicate efforts, this seems like a pretty substantial change for follow seaborn.load_dataset, and I think it's easier for this to be merged first before it is refactored to follow a new way of doing things.

[weiji14]

Just one minor docstring suggested change to apply (you'll need to resolve the merge conflict with load_hotspot first though).
Catching up on the discussion at #1436 (comment), if we're moving to follow the seaborn.load_dataset model, then this PR would need substantial changes. Do you want to do the refactoring here or separately?

My thought is to handle it with a separate PR. While I don't want to duplicate efforts, this seems like a pretty substantial change for follow seaborn.load_dataset, and I think it's easier for this to be merged first before it is refactored to follow a new way of doing things.

Ok to approve then, and refactor later.

[weiji14]

/format

[seisman]

Looks good to me.

[weiji14]

@willschlitzer, before you merge this, could you please add an entry under https://github.com/GenericMappingTools/pygmt/blob/main/doc/api/index.rst#datasets? (Also would be nice to sort the entries alphabetically). Thanks!