Add paragraph.

src/intermediate/mod.rs

@@ -5,6 +5,7 @@ mod element;
 mod heading;
 mod object;
 mod page;
+mod paragraph;
 mod plain_text;
 mod registry;
 mod section;
@@ -17,6 +18,7 @@ pub(crate) use element::IElement;
 pub(crate) use heading::IHeading;
 pub(crate) use object::IObject;
 pub(crate) use page::BlogPostPage;
+pub(crate) use paragraph::IParagraph;
 pub(crate) use plain_text::IPlainText;
 pub(crate) use section::ISection;
 pub(crate) use target::ITarget;