Support natural language headers for embedded nodes

[mindsocket]

This needs more thinking through.

Currently we support bulleted lists annotated with type anchors or inline properties. This can get a bit verbose. Instead we could support a heading that matches a no type and then treat all bulleted points underneath that as being of that type. Example below...

... Existing page content, up to mission level

### Goals
- A goal - we know this is a goal because the heading above matches a node type (singular, lower case: goal)
- Another goal

It's not yet clear yet that this is going to be helpful, so let's park this idea for now

[mindsocket]

For natural language support, we could add natural language terms to HierarchyLevel (design TBD - could be a plural field, or a synonyms field, or similar) for the purposes of supporting this idea. This would make the system more flexible in recognizing various forms of headings while maintaining a canonical type system.