html to markdown
perl -ne 's|<a.*?href="(.*?)".*?>(.*?)<\/a>|[\2](\1)|g;print'
markdown to html
perl -ne 's|\[(.*?)\]\s*?\((.+?)\)|<a href=\"\2\">\1</a>|g;print'
html to markdown
perl -ne 's|<a.*?href="(.*?)".*?>(.*?)<\/a>|[\2](\1)|g;print'
markdown to html
perl -ne 's|\[(.*?)\]\s*?\((.+?)\)|<a href=\"\2\">\1</a>|g;print'