Oh, we’re reading you Tania Rascia (@taniarascia)! Even easier for you it looks like Chris Biscardi (@chrisbiscardi) has already built out some infrastructure for webmentions on Gatsby(@gatsbyjs).
Chris has written a bit about his process as well: Building Gatsby Plugin Webmentions.
Tom, for the basics of what Webmention is you might try this intro article Webmentions: Enabling Better Communication on the Internet.
To get started quickly, just to have the notifications, you might try creating an account with Webmentions.io and put the endpoint into the
<head> of your site so you can receive them in the erstwhile on a separate service and worry about direct integration at a later date. As I recall Aaron Gustafson has a Webmention.io Jekyll Plugin for display and some of the outline is covered in this recent article by Max Böck.
If necessary, you can get help in the #Dev channel of the IndieWeb chat.
I have been using Blot, a simple blogging platform with no interface, for quite some time now for running my blog. I am not alone when I say this, but am mighty impressed with how simple it is to post things on blot and maintain the overall site. They are just some files in Dropbox - that’s about ...
A nice little tutorial for using Webmention.io with content management systems like Blot.