Update Parsedown library to version 1.7.4
Update Parsedown library to version 1.7.4

This commit updates the Parsedown library to version 1.7.4. The patch to
prevent tab indentations in code blocks from being converted to spaces
is already applied here.

See: 78c5974cd34559d0130d8be509935e2c992cd9ca

Nerdmind/Blog,Nerdmind/Blog