Streamline blogpost OG generation

Also fix a tiny wrong `<` that moved the blogpost OG tags in the body.
5 jobs for 48-opengraph-protocol in 3 minutes and 11 seconds (queued for 4 seconds)
latest
Status Job ID Name Coverage
  Build
passed build:latest #71706

00:02:24

passed build:production #71708

00:02:16

passed build:production:subpath #71707

00:02:10

 
  Test
passed test:htmlproofer #71709

00:00:53

passed test:htmlproofer:subpath #71710

00:00:50