fix: task lists not rendered when GFM is disabled (#1825)

* Fix #1823 - task lists are rendered even when GFM is disabled.

* end file with a new line

Co-authored-by: Tony Brix <tony@brix.ninja>

Author: TheCloudlessSky

src/Tokenizer.js

@@ -278,11 +278,13 @@ module.exports = class Tokenizer {
         }
 
         // Check for task list items
-        istask = /^\[[ xX]\] /.test(item);
-        ischecked = undefined;
-        if (istask) {
-          ischecked = item[1] !== ' ';
-          item = item.replace(/^\[[ xX]\] +/, '');
+        if (this.options.gfm) {
+          istask = /^\[[ xX]\] /.test(item);
+          ischecked = undefined;
+          if (istask) {
+            ischecked = item[1] !== ' ';
+            item = item.replace(/^\[[ xX]\] +/, '');
+          }
         }
 
         list.items.push({

test/specs/new/list_tasks_non_gfm.html

@@ -0,0 +1,5 @@
+<ul>
+<li>[ ] A</li>
+<li>[x] B</li>
+<li>[ ] C</li>
+</ul>

test/specs/new/list_tasks_non_gfm.md

@@ -0,0 +1,7 @@
+---
+gfm: false
+description: Task lists are ignored when not using GFM
+---
+- [ ] A
+- [x] B
+- [ ] C