Adds a section to a Brix page version.
mix brix.gen.section SLUG TEMPLATE [--content-dir PATH] [--version VER]
[--position NN] [--parent SECTION]
[--field FIELD]Examples
mix brix.gen.section home hero
mix brix.gen.section home cta --position 10
mix brix.gen.section home testimonial_card --parent 05-reviews-sectionNested children
Use --parent to create a child section inside a parent's .children/ directory.
The --field flag specifies which children field (defaults to "children").
The child template is validated against the parent's of: constraint.