Borrow chapters function

[cansavvy]

In an Rmarkdown document you can do this and it will knit the markdown into your course!

```{r, echo=FALSE, results='asis'}
cow::borrow_chapter(doc_path = "docs/02-chapter_of_course.md", repo_name = "jhudsl/DaSL_Course_Template_Bookdown")
```

[cansavvy]

Everything is all polished up!

[cansavvy]

All that's left is that same windows specific package problem #7 Otherwise this is set!