Revise documentation

[boshek]

From the review:

Lastly. I would consider revising your tidyhydat-package documentation. This is frequently the first interaction a user might have with the package. Currently it is very focused on the data format and output style (tidy), not the data itself. This documentation (along with a Vignette) would be an excellent place to better give an overview of the data available. What data are availble through this package? Stream/river level, flow, and it seems, sediment flux estimates at daily and monthly timescales (also real-time in some cases)?

On the overview side, I'd recommend, if possible, pointing to further HYDAT documentation. A lot of the documentation here relies on the user's knowledge of the HYDAT database. For example, much of the function documentation refers to the functions as "Provides wrapper to turn the XXX table in HYDAT into a tidy data frame." which implies knowledge of the HYDAT database.

Also from the review:

Generally, I'm a big fan of every exported function having at least one functional example. It helps immensely, especially when teaching new R users. A package such as this could be very useful for new R users with a flavor for Canadian hydrology.

It would be really cool to have (maybe another) vignette that works through a complete analysis. Maybe from looking for data, to getting the data, to visualizing the data. Alternatively, maybe expanding the help files a bit to describe more completely what is returned from each function/data set. It wasn't obvious to me until I ran the function and looked at the result.

[boshek]

Also partially addressed here: 328822c