Move and rename "Accessibility concerns" section in HTML element page…

… template (mdn#33628)

* move and rename accessibility section

* remove 'optionally'

files/en-us/mdn/writing_guidelines/page_structures/page_types/html_element_page_template/index.md

@@ -103,6 +103,10 @@ Include a table of the events fired on this type of element, if any.
 | event 2    | Explain briefly when it is fired |
 | etc.       |                                  |
 
+## Accessibility
+
+Warn of any potential accessibility concerns that exist with using this element, and how to work around them. Remove this section if there are none to list.
+
 ## Examples
 
 Note that we use the plural "Examples" even if the page only contains one example.
@@ -141,10 +145,6 @@ See our guide on how to add [code examples](/en-US/docs/MDN/Writing_guidelines/P
 > For examples of this API, see [the page on fetch()](https://example.org).
 > ```
 
-## Accessibility concerns
-
-Optionally, warn of any potential accessibility concerns that exist with using this element, and how to work around them. Remove this section if there are none to list.
-
 ## Technical summary
 
 <table class="properties">