Makefile,README.md: Improve installation target

 a.) Add build products to .gitignore
 b.) Improve `make install` target to automatically copy script and
 touch scratch file.
 c.) Reflect changes in README.md

Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Merge pull request #3 from victoredwardocallaghan/master

Makefile,README.md: Improve installation target