Migrate content syntax via script

The changes in this commit were auto-generated by running

tool/migrate.sh

Following this commit, the Dactyl build no longer works but the Redocly
build (mostly) should.

content/_snippets/macros/page-children.md

@@ -1,16 +1 @@
-{% macro page_children(pg, depth, max_depth, show_blurbs) %}
-{% if pg.children %}
-{% if depth == 1 %}<ul class="children-display">{% endif %}
-  {% for child in pg.children %}
-<li class="level-{{depth}}"><a href="{{child.html}}">{{child.name}}</a>
-  {% if child.status == "not_enabled" %}:not_enabled:{% endif %}
-  <p class="blurb child-blurb">{{child.blurb}}</p>
-</li>
-  {% if child.children and depth < max_depth %}
-{{ page_children(child, depth+1, max_depth, show_blurbs) }}
-  {% endif %}
-  {% endfor %}
 
-{% if depth == 1 %}</ul><!--/.children-display-->{% endif %}
-{% endif %}
-{% endmacro %}