Updated README.md file

Added a short description of the repository and information about
which version of liferay was used
Added intial version of Sticky Footer template

This template will cause issues with themes that include footers;
it will hide any footer content and show the sticky footer instead.
A page layout with at least one empty row at the end is needed to
prevent the footer from covering other content. Also has issues at
narrow widths: sticky footer content can cover entire window.
Added initial version of Carousel Site Template

All content is formatted by structures. Currently, the three-column
layout for the heading posts is created by using nested portlets,
not a unique layout. Some text styling is set in the featurette
template and might override theme styling. Future work would be to
add an option to include text in the carousel.