[css-gaps-1] Use commas instead of slashes for *-rule shorthands. #11496 (#12051)

Author: kbabbitt

css-gaps-1/Overview.bs

@@ -844,28 +844,23 @@ Gap decoration shorthands: The 'column-rule' and 'row-rule' properties {#gap-dec
 	</pre>
 
 	<pre class='prod'>
-		<dfn>&lt;gap-rule-list&gt;</dfn>        = <<gap-rule-or-repeat>> [ / <<gap-rule-or-repeat>> ]*
+		<dfn>&lt;gap-rule-list&gt;</dfn>        = <<gap-rule-or-repeat>>#
 
-		<dfn>&lt;gap-auto-rule-list&gt;</dfn>   = [ [ <<gap-rule-or-repeat>> ] / ]*
-								             <<gap-auto-repeat-rule>>
-								             [ / [ <<gap-rule-or-repeat>> ] ]*
+		<dfn>&lt;gap-auto-rule-list&gt;</dfn>   = <<gap-rule-or-repeat>>#? ,
+								             <<gap-auto-repeat-rule>> ,
+								             <<gap-rule-or-repeat>>#?
 
-		<dfn>&lt;gap-rule-or-repeat&gt;</dfn>   = [ <<gap-rule>> | <<gap-repeat-rule>> ]
+		<dfn>&lt;gap-rule-or-repeat&gt;</dfn>   = <<gap-rule>> | <<gap-repeat-rule>>
 
-		<dfn>&lt;gap-repeat-rule&gt;</dfn>      = repeat( [ <<integer [1,∞]>> ] , [ <<gap-rule>> ]# )
+		<dfn>&lt;gap-repeat-rule&gt;</dfn>      = repeat( <<integer [1,∞]>> , <<gap-rule>># )
 
-		<dfn>&lt;gap-auto-repeat-rule&gt;</dfn> = repeat( auto , [ <<gap-rule>> ]# )
+		<dfn>&lt;gap-auto-repeat-rule&gt;</dfn> = repeat( auto , <<gap-rule>># )
 
-		<dfn>&lt;gap-rule&gt;</dfn>             = [ <<line-width>> || <<line-style>> || <<color>> ]
+		<dfn>&lt;gap-rule&gt;</dfn>             = <<line-width>> || <<line-style>> || <<color>>
 	</pre>
 
 	These shorthands set the corresponding width, style, and color properties as a set.
 
-	Issue: Are the slashes to separate values into tuples the right way to structure this?
-	Or would it be safe to allow free-form mixing, for example 'column-rule: 1px 5px solid black'?
-	Note that commas are reserved for future extension of the grammar to support
-	<a href="https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/CSSGapDecorations/explainer.md#placement-of-gap-decorations">gap decoration areas</a>.
-
 Bi-directional gap decoration shorthands: The 'rule-color', 'rule-style', 'rule-width', and 'rule' properties {#rule-bi-directional}
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