Fixing display of footnotes by reverting Parsedown

An update to Parsedown, one of the packages that Grav uses to process Markdown, broke the display of footnotes and image captions. The update was necessary for security reasons that I don't understand, to do with processing HTML, I believe. While the Parsedown people are working on a proper fix, it seemed OK for me to revert to an earlier version as long as I am the only person adding footnotes and image captions, and as long as I trust myself not to do malicious stuff.

Andy Miller graciously provided a step-by-step:

1. Edit composer.json in the root of Grav
2. Remove the security checking dependency: "roave/security-advisories": "dev-master"
4. Edit the parsedown entry to force the last pre-security fixed version: "erusev/parsedown": "1.6.4"
6. From terminal run `composer update --no-dev`

Job done.

And indeed it was, locally. On the live server I ran into trouble because Composer was not installed, and wouldn't install because the .phar extension was missing from my PHP. Fiddling with php.ini on DreamHost was more than I bargained for this morning, so I just uploaded the changed composer.json file and the /parsedown folder and hoped for the best.

It worked there too, so I am very happy. I hope I haven't created problems for the future.