20987 initial CSS container queries updates

[bsmth]

This PR is a first pass for improving the documentation for CSS container queries.
I expect there to be some further follow-ups to add more details and (live/interactive) examples where necessary or other pages that I've missed here.

Highlights

Updates:

• css_container_queries most of the updates occur in this doc including
  • summaries of the properties with examples of their usage
  • new diagrams
  • links to new properties & related docs
• length: added information to this document about "container query length units" which allow you to specify a length relative to the dimensions of a query container.
• media queries page: added references to container queries with a new diagram explaining media queries

Additions:

• @container at-rule
• container-name property
• container-type property
• container shorthand property (simplifies container name and type to one declaration)

[github-actions]

Preview URLs (12 pages)

• /en-US/docs/Learn/CSS/CSS_layout/Responsive_Design
• /en-US/docs/Web/CSS/@container
• /en-US/docs/Web/CSS/CSS_Container_Queries
• /en-US/docs/Web/CSS/CSS_Containment
• /en-US/docs/Web/CSS/CSS_Values_and_Units
• /en-US/docs/Web/CSS/Media_Queries/Using_media_queries
• /en-US/docs/Web/CSS/Media_Queries
• /en-US/docs/Web/CSS/contain
• /en-US/docs/Web/CSS/container-name
• /en-US/docs/Web/CSS/container-type
• /en-US/docs/Web/CSS/container
• /en-US/docs/Web/CSS/length

Flaws (1)

Note! 11 documents with no flaws that don't need to be listed. 🎉

URL: /en-US/docs/Web/CSS/CSS_Values_and_Units
Title: CSS values and units
Flaw count: 1

• macros:
  • /en-US/docs/Web/CSS/toggle does not exist

(this comment was updated 2022-11-14 15:48:26.887119)

[estelle]

Reviewed the at-rule. Still working on it.

For the @container page:

• The "descriptors" are not descriptor. They are query features.
• We're missing the height feature.
• People don't fully understand inline and block direction, so that needs to be linked (not a give).
• The container condition is not limited to feature query; only single feature query example and syntax is shown
• The style() option of the container query is not discussed
• Query modifiers are missing
• stringing multiple conditions with modifiers is missing
• No information is provided on the container name syntax
  • a custom ident is case sensitive
  • can not be a keyword that may conflict or the word default
  • can start with --, which is a different kind of ident, but i forget the name
  • is not quoted

[bsmth]

Tracking review suggestions:

@container

• The "descriptors" are not descriptor. (see review comment)
• We're missing the height feature. (done in cd6eaff)
• People don't fully understand inline and block direction, so that needs to be linked (not a give). (done in cd6eaff)
• The container condition is not limited to feature query; only single feature query example and syntax is shown (added in 23a1b02)
• The style() option of the container query is not discussed (added in 23a1b02)
• Query modifiers are missing (added in 23a1b02)
• stringing multiple conditions with modifiers is missing (added in 23a1b02)
• No information is provided on the container name syntax (added in 1a96d30)
  • a custom ident is case sensitive
  • can not be a keyword that may conflict or the word default
  • can start with --, which is a different kind of ident, but i forget the name
  • is not quoted

[bsmth]

Thanks @estelle

Note:
This one was merged early, there are unaddressed review comments that I'll carry over to a new PR.