Update and rename A2MarkdownDraft.md to A2MarkdownDraft.Rmd

Hi I've made a few changes so that you can now create a PDF from the *A2MarkdownDraft* file:

- Gave the file a *.Rmd* file extension rather than *.md*

- The header was missing a colon after `pdf_document` and before `toc: true`, this indicates that `toc` is a sub-value of `pdf_document`. I added in the missing colon.

- Originally you set the working directory in a chunk header. Remember that all R commands should be placed *after* the chunk header, e.g.:

```{S}
```{r echo=FALSE}
setwd('/blah/blah')
```

I don't think you actually need to set the R working directory for this paper, so I just deleted this code chunk.

- It seems like you wrote the original text in Word, this introduced a lot of weird encodings of the em dash  (`-`) that LaTeX doesn't understand. We'll actually talk about character encodings on Monday. But I also fixed them in your text.