Check link isExternal before adding target="_blank" (#1211)

Paul Trotter

2024-06-17 42640bceb57c450d5c2427bd2b449827468d0ede

 quartz/components/styles/legacyToc.scss

@@ -12,7 +12,7 @@
      margin: 0;
    }
  }
    

  & ul {
    list-style: none;
    margin: 0.5rem 1.25rem;