Update heading_elements/index.md (mdn#28270)

* Update heading_elements/index.md

Section Accessibility Concerns / Navigation:
    Insert two missing words to fix the sentence:

Changed from:
    " ...is jumping from heading to quickly determine..."

To:
    "...is jumping from heading to heading to quickly determine..."

* Update files/en-us/web/html/element/heading_elements/index.md

---------

Co-authored-by: Hamish Willee <[email protected]>

files/en-us/web/html/element/heading_elements/index.md

@@ -129,7 +129,7 @@ The following code shows a few headings with some content under them.
 
 ### Navigation
 
-A common navigation technique for users of screen reading software is jumping from heading to quickly determine the content of the page. Because of this, it is important to not skip one or more heading levels. Doing so may create confusion, as the person navigating this way may be left wondering where the missing heading is.
+A common navigation technique for users of screen reading software is to quickly jump from heading to heading to in order to determine the content of the page. Because of this, it is important to not skip one or more heading levels. Doing so may create confusion, as the person navigating this way may be left wondering where the missing heading is.
 
 **Don't do this:**