Function from_read_coloured 

pub fn from_read_coloured<R, FMap>(
    input: R,
    width: usize,
    colour_map: FMap,
) -> Result<String, Error>
where
    R: Read,
    FMap: Fn(&[RichAnnotation], &str) -> String,

Reads HTML from input, and returns text wrapped to width columns.

The text is returned as a Vec<TaggedLine<_>>; the annotations are vectors of RichAnnotation. The “outer” annotation comes first in the Vec.

The function colour_map is given a slice of RichAnnotation and should return a pair of static strings which should be inserted before/after a text span with that annotation; for example a string which sets text colour and a string which sets the colour back to the default.