An alternative to the simple gallery would be this version, which displays the post ins a lightbox. The setup basically is the same, the include makes all the difference.

Galleries are defined in a data-sheet, set type and gallery-id in front matter and include gallery_lightbox.html within the content.

front matter
layout: post-full
type: gallery
    - images:
      - filename: gallery-1.jpg
        alttext: Bloom Flat
      - filename: gallery-2.jpg
        alttext: Bloom
      - filename: gallery-3.jpg
        alttext: Blossom in a Star
      - filename: gallery-4.jpg
        alttext: Blossom
      - filename: gallery-5.jpg
        alttext: Bubbly Bloom
      - filename: gallery-6.jpg
        alttext: Rays of Gold
      - filename: gallery-7.jpg
        alttext: Exotic
      - filename: gallery-8.jpg
        alttext: Filled out

post content

{% include gallery_lightbox.html %}