updatet the example

add some depedencies to calc the terminal size

add peiqi example image

change the char width to 0.5

add example

remove some useless code

add new method to convert a image from filename directly

Update README.md

Update README.md

rename example images

Update README.md

add more ascii images

Update README

UPDATE README

add lufei ascii image

add example images

update README file

add convert package to convert a image to ascii matrix

update README file

add ascii package to convert a image pixel to ascii