Revert "build: publish multiple formats"

Reverts enzedonline/quill-blot-formatter2#16 Merged in error, prior to testing PR code. Apparently the compiled packages had not been verified as working correctly prior to submitting the PR. The USM was not configured correctly and still contained many errors in the compiled code when including the missing target and globals flags. Microbundle seems to not compile this project correctly. I'm reverting back to WebPack, I'll look at adding cjs and esm to the outputs shortly.