Added functions to draw with bigger font size

drawUnicodeBig, drawUnicodeStringBig, drawCharBig, drawStringBig, drawNumberBig
Added functions to draw with bigger font size

made getTemperature() public
Fixed small spelling mistake
Added 'Big' functions to keywords for syntax highlighting
Added 'big' functions to example
Added alias for sd_clear as clearDisplay which correctly clears the display, unlike the existing clear function
Added an example which shows how to display the temp and refresh the display with new data in a loop
keywords files are picky. Fixed to conform to pickyness
Updated the readme to remove html elements and add documentation on clearDisplay()
Merge pull request #2 from harrisonhjones/master

Big functions, clear display, and examples