Iteration on the initial Course Syllabus

[drphilmarshall]

Not yet ready for review! But here's where I'm addressing my own review comments in PR #125:

• Try splitting session 1 in two, to Basics followed by Getting Started
• Add links to missing resources (esp DIA)
• Remove projects and start issues instead - and then link issues back to syllabus.

I'll add more to-do's to the list above as I go, and then request a review from Alex when I'm done.

[drphilmarshall]

OK @kadrlica I worked my way through sessions 1-5, adding links to a few more resources, doing some moving around of topics, and so on. I started two new project opportunity issues based on the gaps in the syllabus, #129 (Visualization: RGB cutouts) and #131 (Source detection: Explain everything). See what you think - I'm hoping this might be enough to get us started on Friday, when we could carry on and make some more issues, perhaps with the help of anyone looking for a new project.

[kadrlica]

Looks good! The consistent formatting breaks down after Session 5, but I think that's ok. I think it's definitely ok for Friday, and we can continue to work on this an flesh it out.

[kadrlica]

Both the Source/Object measurement and Astrometric calibration are labeled section "10".

[kadrlica]

@drphilmarshall I'm not sure how to do the joint merge of this PR with #125. What are best practices?

[drphilmarshall]

Thanks @kadrlica ! I fixed the numbering, and completed the job of removing the projects to the issue list. I'll merge this PR, since its approved and I'm the owner; then I'll approve your PR for you to tweak and merge.