doc/lua-filters.md: document 'Figure' type and constructor

doc/lua-filters.md

@@ -1124,6 +1124,36 @@ Fields:
 `tag`, `t`
 :   the literal `Div` (string)
 
+### Figure {#type-figure}
+
+Figure with caption and arbitrary block contents.
+
+Values of this type can be created with the
+[`pandoc.Figure`](#pandoc.figure) constructor.
+
+Fields:
+
+`content`
+:   block content ([Blocks][])
+
+`caption`
+:   figure caption ([Caption][])
+
+`attr`
+:   element attributes ([Attr][])
+
+`identifier`
+:   alias for `attr.identifier` (string)
+
+`classes`
+:   alias for `attr.classes` ([List][] of strings)
+
+`attributes`
+:   alias for `attr.attributes` ([Attributes][])
+
+`tag`, `t`
+:   the literal `Figure` (string)
+
 ### Header {#type-header}
 
 Creates a header element.
@@ -2370,6 +2400,8 @@ Usage:
 [Citations]: #type-citation
 [ColSpec]: #type-colspec
 [CommonState]: #type-commonstate
+[Div]: #type-div
+[Figure]: #type-figure
 [Image]: #type-image
 [Inline]: #type-inline
 [Inlines]: #type-inlines
@@ -2717,6 +2749,23 @@ Parameters:
 
 Returns: [Div] object
 
+### `Figure (content[, caption[, attr]])` {#pandoc.div}
+
+Creates a [Figure][] element.
+
+Parameters:
+
+`content`
+:   figure block content
+
+`caption`
+:   figure caption
+
+`attr`
+:   element attributes
+
+Returns: [Figure][] object
+
 ### `Header (level, content[, attr])` {#pandoc.header}
 
 Creates a header element.