[css-grid][css-sizing] Define some property-specific functions as functions (not values). w3c#7682

Author: tabatkins

css-grid-1/Overview.bs

@@ -1555,7 +1555,7 @@ Track Sizes</h4>
 			When appearing outside a ''minmax()'' notation,
 			implies an automatic minimum (i.e. ''minmax(auto, <<flex>>)'').
 
-		<dt><dfn lt="minmax()">minmax(<var>min</var>, <var>max</var>)</dfn>
+		<dt><dfn function lt="minmax()">minmax(<var>min</var>, <var>max</var>)</dfn>
 		<dd>
 			Defines a size range
 			greater than or equal to <var>min</var>
@@ -1601,7 +1601,7 @@ Track Sizes</h4>
 			Represents the largest <a>min-content contribution</a>
 			of the  <a>grid items</a> occupying the <a>grid track</a>.
 
-		<dt><dfn lt="fit-content()">fit-content( <<length-percentage>> )</dfn>
+		<dt><dfn function lt="fit-content()">fit-content( <<length-percentage>> )</dfn>
 		<dd>
 			Represents the formula
 			<code>max(<var>minimum</var>, min(<var>limit</var>, ''max-content''))</code>,

css-grid-2/Overview.bs

@@ -1639,7 +1639,7 @@ Track Sizes</h4>
 			When appearing outside a ''minmax()'' notation,
 			implies an automatic minimum (i.e. ''minmax(auto, <<flex>>)'').
 
-		<dt><dfn lt="minmax()">minmax(<var>min</var>, <var>max</var>)</dfn>
+		<dt><dfn function lt="minmax()">minmax(<var>min</var>, <var>max</var>)</dfn>
 		<dd>
 			Defines a size range
 			greater than or equal to <var>min</var>
@@ -1685,7 +1685,7 @@ Track Sizes</h4>
 			Represents the largest <a>min-content contribution</a>
 			of the  <a>grid items</a> occupying the <a>grid track</a>.
 
-		<dt><dfn lt="fit-content()">fit-content( <<length-percentage>> )</dfn>
+		<dt><dfn function lt="fit-content()">fit-content( <<length-percentage>> )</dfn>
 		<dd>
 			Represents the formula
 			<code>max(<var>minimum</var>, min(<var>limit</var>, ''max-content''))</code>,

css-sizing-3/Overview.bs

@@ -507,7 +507,7 @@ Sizing Values: the <<length-percentage [0,∞]>>, ''width/auto'' | ''max-width/n
 			i.e.
 			<code>min(''width/max-content'', max(''width/min-content'', ''width/stretch''))</code>.
 -->
-		<dt><dfn>fit-content(<<length-percentage [0,∞]>>)</dfn>
+		<dt><dfn function lt="fit-content()">fit-content(<<length-percentage [0,∞]>>)</dfn>
 		<dd>
 			Use the fit-content formula
 			with the <a>available space</a> replaced by the specified argument,