Move objects to a lower exit class.

Paragraph's exit matcher which detects elements was causing the plain list parser to exit after the first item was parsed which was causing significant amounts of re-parsing.

src/parser/text_markup.rs

@@ -179,7 +179,7 @@ fn _text_markup_object<'r, 's, 'x>(
     let text_markup_end_specialized = text_markup_end(open.into());
     let parser_context =
         context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
-            class: ExitClass::Beta,
+            class: ExitClass::Gamma,
             exit_matcher: &text_markup_end_specialized,
         }));
 
@@ -229,7 +229,7 @@ fn _text_markup_string<'r, 's, 'x>(
     let text_markup_end_specialized = text_markup_end(open.into());
     let parser_context =
         context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
-            class: ExitClass::Beta,
+            class: ExitClass::Gamma,
             exit_matcher: &text_markup_end_specialized,
         }));
 
@@ -338,7 +338,7 @@ fn _rematch_text_markup_object<'r, 's, 'x>(
     let text_markup_end_specialized = text_markup_end(open.into());
     let parser_context =
         context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
-            class: ExitClass::Beta,
+            class: ExitClass::Gamma,
             exit_matcher: &text_markup_end_specialized,
         }));