fixed the issue can the filename is null

Update README.md

update the git ignore file

Parse the cli args

Add the method to fit the screen

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