(feat): Unpack extensions into complex function types #8

The more in-depth we use extensions, the more likely is is that we need custom extensions. New `UnpackExtensions` function in the high package makes this easy. Low level models have been updated to support feature fully and docs added in README and examples as well.

Signed-off-by: Dave Shanley <dave@quobix.com>

datamodel/low/base/xml.go

@@ -33,6 +33,7 @@ func (x *XML) Build(root *yaml.Node, _ *index.SpecIndex) error {
 	return nil
 }
 
+// GetExtensions returns all Tag extensions and satisfies the low.HasExtensions interface.
 func (x *XML) GetExtensions() map[low.KeyReference[string]]low.ValueReference[any] {
 	return x.Extensions
 }