Fix typo and bump date

Author: mattcone

_tools/typemill.md

@@ -39,7 +39,7 @@ syntax:
   - id: footnotes
     available: y
   - id: heading-ids
-    available: yes
+    available: y
     notes: "Can be activated in the settings."
   - id: definition-lists
     available: y

tools.md

@@ -2,7 +2,7 @@
 layout: tools
 title: Tools
 description: Applications and components that support Markdown.
-last_modified_at: 2025-06-19
+last_modified_at: 2025-06-24
 ---
 
 <div class="row">