Record the list item indent depth in the context tree.

src/parser/plain_list.rs

@@ -16,6 +16,7 @@ use nom::sequence::tuple;
 use super::combinator::context_many_till;
 use super::error::Res;
 use super::paragraph::paragraph_end;
+use super::parser_context::ContextElement;
 use super::text::space;
 use super::text::text_element;
 use super::token::ListItem;
@@ -31,6 +32,7 @@ pub fn plain_list<'r, 's>(context: Context<'r, 's>, i: &'s str) -> Res<&'s str,
 pub fn item<'r, 's>(context: Context<'r, 's>, i: &'s str) -> Res<&'s str, ListItem<'s>> {
     let (remaining, leading_whitespace) = space0(i)?;
     let indent_level = leading_whitespace.len();
+    let list_item_context = context.with_additional_node(ContextElement::ListItem(indent_level));
     let (remaining, (bul, countset, check, tg, sp, (contents, end))) = tuple((
         bullet,
         opt(tuple((space, counter_set))),
@@ -38,7 +40,7 @@ pub fn item<'r, 's>(context: Context<'r, 's>, i: &'s str) -> Res<&'s str, ListIt
         opt(tuple((space, item_tag))),
         space,
         // TODO: This context should probably be something involving the item
-        context_many_till(context, text_element, item_end),
+        context_many_till(&list_item_context, text_element, item_end),
     ))(remaining)?;
 
     let elements = contents