Added preloadImages() to load all page images and added index.html

- If new images are added, just put their pathname (relative to the images folder) in the imgs array within preloadImages().
- Renamed teatime.html to index.html
- Deleted an old log statement.
Merge branch 'master' into gh-pages
Merge branch 'gh-pages' of https://github.com/Bates550/teatime into gh-pages