UPDATE Nov 17 2018
I’ve changed my mind. I’m now using an automatic build server that takes any changes I make, runs the static site generator and pushes it to my webserver.
Saves a lot of stuffing about.
I followed this guide which was helpful.
Okay. Just for the record, here's the long (and pretty complicated) way to get a new blog post up.
1. Write on my computer (iMac)
2. Check in the post to Git (locally)
3. Push the changes to my blog repo on BitBucket
4. Log into my Virtual Machine (local) where Jekyll is installed (see note 1)
5. Pull the changes from Git (BitBucket)
6. Run Jekyll `jekyll build`
7. rsync the new _site folder, so the changes appear live on this blog
8. Check in the new _site changes
9. Commit to Git, push
10. Pull changes from Git to my iMac (for backing up/records)
Should have just stayed with Wordpress.