html_getLinks() function

[jonathancallahan]

A start on this function is found in local_TODO/html_getLinks.R.

That function should have enough advice to get you going. You should

• copy the file into the R/ directory
• walk through the code that currently exists and make sure it works
• learn just enough about xml2 to finish up the function
• source and test the function on a variety of URLs and local html files
• create wrapper functions html_getLinkNames() and html_getLinkUrls() that return only the linkName or linkUrl columns as vectors. These should exist inside the same html_getLinks.R file and all three functions should share a single documentation page.