video element content is media alternative for text: "labeled" needs a definition [ab4d13]

[WilcoFiers]

In expectation 2, the term "labeled" is used. The note says this doesn't mean the label element, but it doesn't say what is meant here. If this is meant to reference the WCAG definition of label, it's missing a link. But even that definition is ambiguous due to the use of the phrase "component with a text alternative" which is vague.

This rule is used in a few composite rules, which are effected by this issue:

• https://act-rules.github.io/rules/eac66b
• https://act-rules.github.io/rules/c5a4ea
• https://act-rules.github.io/rules/c5a4ea