robxp: Parse a `robots.txt` file & create a `robxp` object
Description
This function takes in a single element character vector and parses it into
a `robxp` object.
Usage
robxp(x)
Value
a classed object holding an external pointer to parsed robots.txt data
Arguments
x
either an atomic character vector containing a complete `robots.txt`` file
_or_ a length >1 character vector that will concatenated into a single string _or_
a `connection` object that will be passed to [readLines()], the result of which
will be concatenated into a single string and parsed and the connection will be closed.