Hex Odd Columns showing Hex Even Columns in readme

[martinmolin]

Not really a feature/bug report. Sorry about the lack of template usage :)

The image hex_tile_odd_cols.png is the same as the hex_tile_even_cols.png and the title of the window in the image says Hex Even Columns.

https://github.com/joshuajbouw/bevy_tilemap/blob/master/docs/img/hex_tile_odd_cols.png