update links for section 1

_includes/links.md

 {% include base_path.html %}
 [cc-by-human]: https://creativecommons.org/licenses/by/4.0/
 [cc-by-legal]: https://creativecommons.org/licenses/by/4.0/legalcode
+[cdh]: https://cdh.carpentries.org/
 [ci]: http://communityin.org/
 [coc-reporting]: https://docs.carpentries.org/topic_folders/policies/incident-reporting.html
 [coc]: https://docs.carpentries.org/topic_folders/policies/code-of-conduct.html
@@ -24,10 +25,12 @@
 [lesson-aio]: {{ relative_root_path }}{% link aio.md %}
 [lesson-coc]: {{ relative_root_path }}{% link CODE_OF_CONDUCT.md %}
 [lesson-example]: https://carpentries.github.io/lesson-example/
+[lesson-example-blockquotes]: https://carpentries.github.io/lesson-example/04-formatting/index.html#special-blockquotes
 [lesson-license]: {{ relative_root_path }}{% link LICENSE.md %}
 [lesson-mainpage]: {{ relative_root_path }}{% link index.md %}
 [lesson-reference]: {{ relative_root_path }}{% link reference.md %}
 [lesson-setup]: {{ relative_root_path }}{% link setup.md %}
+[markdown-cheatsheet]: https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet
 [mit-license]: https://opensource.org/licenses/mit-license.html
 [morea]: https://morea-framework.github.io/
 [numfocus]: https://numfocus.org/