Test on PHP 8.1

v0.8.1

version 0.8.0

Merge pull request #124 from aidantwoods/fix/depth-first

Recursion should be depth first and latest upstream beta fixes

improve readme

version 0.7.0

resolve #39

add a version constant

back links on the next line for footnotes that don't end with paragraphs

parsedown 1.4