[whatwg] Change description of em element

[Joseph Mansfield]

The current semantic meaning of the em element may be confused with that
of the strong element. The specification states that the em element
increases the level of emphasis. There are, however, two definitions of
the word "emphasis":

1. Importance, value, or prominence given to something.
2. Stress laid on a word or words to indicate special meaning or
   particular importance.

While the specification does specify that the em element represents
"stress emphasis" - the form of emphasis that changes the meaning of a
sentence - the frequent use of the word "emphasis" alone may imply
importance. However, the strong element is responsible for importance.
Take the given example:

    <p><em>Cats</em> are cute animals.</p>

The cats are not important - they are stressed. Stress changes the
meaning of the sentence, while importance does not.

To make this clearer, I suggest two options for changing section 4.6.2:

1. Keep the "stress emphasis" from the first sentence and replace all
   other occurences of "emphasis" with "stress emphasis".
2. Replace occurences of "stress emphasis" and "emphasis" with simply
   "stress". This, however, loses the attachment to the element name.

I think this would help with specificity. Thanks for reading.

Regards,
Joseph Mansfield