Removed resolve issue from README

Modifiers are now implemented, as of version 0.2.0
Added whole_line and whole_string

This was inspired by the 'original' JavaScript version's feature:
searchOneLine().
The :whole_line modifier can potentially be violated if, for example,
the user includes "\n" in the search pattern - but there's not much can
be done about that!
Version bump

0.2.0 --> 0.2.1