Buried in your issues tracker you say that you no longer support IE10. ([https://github.com/quilljs/quill/issues/474]). What you support and don't support should be front and center in your documentation so people don't waste their time.
It is front and center on the README
README is frequently just change log. Put it in the docs so it's discoverable by search engines.
No the README.md file is a readme file. The CHANGELOG.md file is the changelog.
After first searching the documentation, then reading the README, I am unable to find what the browser support is.
@kidfribble Are you kidding?

IE does not show up at all anymore. Does this mean that IE 11 is also not supported now?
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IE does not show up at all anymore. Does this mean that IE 11 is also not supported now?