The sprite sheet grid has (0,0) in the lower left, not upper left as documented

[sornas]

Documented here: https://github.com/sornas/lingon/blob/0e779b95386370d37a05b6dbed9cbe6fbbc954d8/src/renderer.rs#L88-L89

Wrong behaviour found here: https://github.com/FredTheDino/PuckNet/blob/fe4c868cdcd270042bd4b4cabb4cea218aa13fbd/text.sy#L3-L6