Share post: Add mastodon to the list of links

[pedropintosilva]

This is an Easy Hack.
Potential mentors: @pedropintosilva

Detailed description and rationale

Each post at the end has a list of social media links where people can use it to share the content. Mastodon is missing

Please try to add mastodon button. This is not an easy hack.

Code pointers

where: themes/hugo-theme-chunky-poster/layouts/partials/sharer.html

• copy and paste this file into /layouts/partials so we can adjust it and thus overwrite the one that comes from that theme

However with mastodon the user might want to share to one of the many existent instances so we cannot simply add a static link as it works with the others social media icons (see partial). Maybe we could use https://github.com/Aly-ve/Mastodon-share-button (?)