Fix #43: Change WORDS_IN_PAGE to get bottom navbar more often
Reduce WORD_IN_PAGE to a smaller value so that the bottom navbar shows up more often on short pages. This is nice to have on mobile devices with small screens.
Value determined experimentally by viewing short pages. If the page doesn't fit on the screen, the bottom navbar should be there. This includes portrait and landscape modes.
Did not try every possible short page. As we find more, we can reduce this value as needed.