Add an introductory PyGMT tutorial

I think there should be a PyGMT tutorial, much like the GMT tutorial. I don’t think it requires as much explanation as what’s happening under the hood, but would ideally recreate the Laboratory Exercises. The PyGMT User Guides cover a variety of topics, but I think following the GMT tutorial gives us a good roadmap on what features to explain for someone trying to learn.

Proposed structure:

• Tutorial introduction (#1607)
• Create a basic map figure using coast (#1607)
• Plot data on a map (#2126)
• Create a contour map (#2126)
• Add a color pallet to a map (#2126)
• Create a 3D map

[liamtoney]

I will likely be providing a PyGMT lesson again for ROSES 2021.

[weiji14]

Welcome @whyjz! Thanks for providing the links, I think that your website is really well thought out, and it fills in an important gap we have on the ‘understanding-orientated’ side of PyGMT’s documentation as mentioned by @meghanrjones at https://github.com/GenericMappingTools/pygmt/issues/770#issuecomment-780680084. The translation system is a very nice feature too, and I hope that we can get more languages going all over the world. Really excited to see where we can go with this by combining efforts!

To start, how about you take a shot at opening a PR to resolve #1059 which is specifically about adding a page on the PyGMT sidebar linking to community contributions like yours. I think you should be familiar enough with the sphinx website theme to figure it out, but let us know if you need help (we can talk more in that #1059 thread).