Plugin should run before replacements/linkify stages

[cocoademon]

URLs in figure captions aren't detected by linkify, as this plugin gets added at the end of the chain.

It would be better if the line to add the plugin was:

md.core.ruler.after('inline', 'implicit_figures', implicitFigures);

This way, linkify, smartquotes, etc can still run on the figure caption.

[arve0]

Thanks for reporting. Fixed in v0.4.0.