Rename file labels for download stats to match collection

[josieg]

Is your feature request related to a problem? Please describe.
When looking at the download stats available under the "Pressbooks" tab on the Open Site's stats page (https://open.bccampus.ca/advocate-for-open-education/open-textbook-stats/), the labels for the different file types are confusing and do not match how we have them in the collection.

Describe the solution you'd like
I would like it if we could rename the labels to they better match the labels we use for the files in the collection.
For example

pdf	Digital PDF
print.pdf	Print PDF
odf	OpenDocument Text
epub	eReader
mobi	Kindle
wxr	Pressbooks XML file
xhtml	HTML
vanillawxr	WordPress XML file

Describe alternatives you've considered
We could also provide a "legend" in the Pressbooks guide for people to refer to.

Additional context
As a textbook author, I would like to be able to understand the download stats so that I can get an idea of how much my book is being used and what file types are the most popular, which may affect future design decisions

[alex-418]

@Josie Took a look and it's not a quick win. Let's tackle it in the near future.

[josieg]

Sounds good!