Identify Featured Tutorials/Guides

[kelle]

We want to have a default set of tutorial content which shows up "above the fold" on the landing page. We need to decide what these should be. Please put your nominations in this issue.

[eblur]

Here are my favorite Astropy tutorials:

• Getting Started with Astropy Coordinates: https://learn.astropy.org/rst-tutorials/1-Coordinates-Intro.html
• Cross matching coordinates: https://learn.astropy.org/rst-tutorials/4-Coordinates-Crossmatch.html
• Quick fit with Astropy modeling: https://learn.astropy.org/rst-tutorials/Models-Quick-Fit.html
• Synthetic images from simulated data: https://learn.astropy.org/rst-tutorials/synthetic-images.html
• Quantities and Units tutorial: https://learn.astropy.org/rst-tutorials/quantities.html
• FITS tables tutorial: https://learn.astropy.org/rst-tutorials/FITS-tables.html
• WCS with FITS images tutorial: https://learn.astropy.org/rst-tutorials/celestial_coords1.html