Gallery decrufting uses add_shortcode() function

[splorp]

According to the current Theme Check Plugin, themes “must not register post types or taxonomies or add shortcodes for post content”, as this is the territory of plugins.

In our case, Tersus uses the add_shortcode() function to decruft and customize the [gallery] shortcode. We either need to find a non-shortcode method of decrufting galleries, or move the functionality to a separate plugin.