added nav link to mimes

Author: TomJaeger

docs/toc_sections/_advanced_usage_toc.yml

@@ -338,6 +338,8 @@
           href: development/services/encrypt.md
         - name: Event Service
           href: development/services/event.md
+        - name: MimeType Service
+          href: development/services/mime.md
         - name: CP/FilePicker Service
           href: development/services/filepicker.md
         - name: CP/Filter Service
@@ -608,6 +610,7 @@
             - name: XML Helper
               href: development/legacy/helpers/xml-helper.md
 
+
         - name: Legacy API Library
           href: development/legacy/api/index.md
           items: