Add alternative lessons

[zenalapp]

Issues

• Resolves # .

Change(s) made

I created an alternative to intro to plotting that:

1. Introduces RStudio, functions, and objects explicitly in an introductory lesson first, and then
2. Introduces reading in files using code and plotting with ggplot2.

I also reorganized some of the plotting in a way that seemed to flow a bit more naturally to me.

Feel free to use none, all, or part of it. Just wanted to share in case it's useful.

Note: I just realized that I changed the data file path so you'd have to change that back.

Checklist

• If you edited any files in _episodes_rmd/, run make lesson-md.
• Run make serve locally to view the website and make sure the formatting renders correctly.
• The build-website workflow succeeds on your most recent commit.

[kelly-sovacool]

Thank you Zena!

We might merge these into one lesson to keep the structure the same as we now have it. I also may tweak the intro to variables & functions based on this short intro R lesson I made for an RNA-seq workshop: https://github.com/BIGslu/2022_ASM_Microbe_RNAseq/blob/main/1_introR/1_intro-R.Rmd

Related to #67