Added TITLE markup to the README so github really render it
Added TITLE markup to the README so github really render it

Also use ':' prefix to annotate source code example which make the
raw README more readable.

Signed-off-by: Franck Bui-Huu <e8d36543077b1c46c7df30e40a2816bc8ffc51e1@gmail.com>

fbuihuu/libtree