Desmos API v1.8.1 released

[desmos-api-announce]

Desmos has released v1.8.1 of the API. You can find the relevant section of the changelog here.

This patch removes the use of a CSS property that was breaking in Safari versions 13 and older. Our CSS minifier was generating a declaration using the `inset` property, which Safari did not add support for until version 14.1. We have adjusted our minification target to support Safari 12.

We are happy to help all of our partners upgrade to v1.8.1 in a timely fashion. Please email Chris Lusto (ch...@desmos.com) with any questions.