Add more realistic regex example

[gcapes]

Fix #930.

[gdevenyi]

I'm neural on this. This regex is far more complex, and the modification also includes the addition of a "-r" option

[deppen8]

Reviving this PR...

I don't feel super strongly that the haiku example needs replaced, but if that is the route you want to go, how about something that searches the DNA sequences in creatures/? I am not a geneticist, but I could imagine you might want to find patterns in the sequences. Here is one that got three hits right away. (It also gets hits if you drop the .{3} for less complexity.)

$ cd creatures/
$ grep -E "^.{3}TTC" basilisk.dat
CATTTCGCGC
TGATTCCAGA
GCCTTCCTAT