Add Sarasa Gothic font

[twse]

@be5invis created a CJK version of Iosevka called Sarasa Gothic. It contains some glyphs from Source Han Sans.

https://github.com/be5invis/Sarasa-Gothic

[chrissimpkins]

Thank you! If you are able to generate the images and Markdown to implement it in the gallery I would be happy to merge this. If not I will do this when I am able to return to the project.