[css-flexbox] Move definitions of flex-basis keywords into shorthand section, to keep the whole definition together.

Author: fantasai

css-flexbox/Overview.bs

@@ -1448,16 +1448,33 @@ The 'flex' Shorthand</h3>
 			and specifies the <dfn dfn>flex basis</dfn>:
 			the initial <a>main size</a> of the <a>flex item</a>,
 			before free space is distributed according to the flex factors.
-			It takes the same values as the 'width' property
-			(except ''flex-basis/auto'' is treated differently)
-			and an additional ''content'' keyword.
-			When omitted from the 'flex' shorthand, its specified value is ''0''.
+			It accepts the same values as the 'width' and 'height' properties
+			(except that ''flex-basis/auto'' is treated differently)
+			plus the ''content'' keyword:
+
+			<dl dfn-type=value dfn-for=flex-basis>
+				<dt><dfn>auto</dfn>
+				<dd>
+					When specified on a <a>flex item</a>, the ''flex-basis/auto'' keyword
+					retrieves the value of the <a>main size property</a> as the used 'flex-basis'.
+					If that value is itself ''auto'', then the used value is ''flex-basis/content''.
 
-			If the specified 'flex-basis' is ''flex-basis/auto'',
-			the used <a>flex basis</a> is the computed value of the flex item’s <a>main size property</a>.
-			If that value is itself ''width/auto'',
-			then the used <a>flex basis</a> is automatically-determined based on its content
-			(i.e. sized as for ''content'').
+				<dt><dfn>content</dfn>
+				<dd>
+					Indicates automatic sizing, based on the <a>flex item</a>’s content.
+		
+					Note: Note that this value was not present in the initial release of Flexible Box Layout,
+					and thus some older implementations will not support it.
+					The equivalent effect can be had by using ''flex/auto''
+					together with a main size ('width' or 'height') of ''width/auto''.
+		
+				<dt><<'width'>>
+				<dd>
+					For all other values,
+					'flex-basis' is resolved the same way as for 'width' and 'height'.
+			</dl>
+
+			When omitted from the 'flex' shorthand, its specified value is ''0''.
 
 		<dt><dfn>none</dfn>
 		<dd>
@@ -1489,11 +1506,12 @@ The 'flex' Shorthand</h3>
 	with a unit or precede it by two flex factors.
 
 <h4 id='flex-common'>
-Common Values of 'flex'</h4>
+Basic Values of 'flex'</h4>
 
 	<em>This section is informative.</em>
 
-	The list below summarizes the effects of the most common 'flex' values:
+	The list below summarizes the effects of the four 'flex' values
+	that respresent most commonly-desired effects:
 
 	<dl>
 		<dt id="flex-initial">''flex: initial''
@@ -1617,31 +1635,18 @@ The 'flex-basis' property</h4>
 	The 'flex-basis' property sets the <a>flex basis</a>.
 	It accepts the same values as the 'width' and 'height' property, plus ''content''.
 
-	<dl dfn-type=value dfn-for=flex-basis>
-		<dt><dfn>auto</dfn>
-		<dd>When specified on a <a>flex item</a>, the ''flex-basis/auto'' keyword
-			retrieves the value of the <a>main size property</a> as the used 'flex-basis'.
-			If that value is also ''auto'', then the used value is ''flex-basis/content''.
-
-		<dt><dfn>content</dfn>
-		<dd>Indicates automatic sizing, based on the <a>flex item</a>’s content.
-
-			Note: Note that this value was not present in the initial release of Flexible Box Layout,
-			and thus some older implementations will not support it.
-			The equivalent effect can be had by using ''flex/auto''
-			together with a main size ('width' or 'height') of ''width/auto''.
-
-		<dt><<'width'>>
-		<dd>For all other values,
-			'flex-basis' is resolved the same way as 'width' in horizontal writing modes [[!CSS21]]:
-			percentage values of 'flex-basis' are resolved against
-			the flex item's containing block, i.e. its flex container,
-			and if that containing block's size is <a>indefinite</a>,
-			the result is the same as a <a>main size</a> of <a value for=width>auto</a>.
-			Similarly, 'flex-basis' determines the size of the content box,
-			unless otherwise specified
-			such as by 'box-sizing' [[CSS3UI]].
-	</dl>
+
+	For all values other than ''flex-basis/auto'' and ''content'' (defined above),
+	'flex-basis' is resolved the same way as 'width' in horizontal writing modes [[!CSS21]].
+	For example, percentage values of 'flex-basis' are resolved against
+	the flex item's containing block (i.e. its flex container)
+	and if that containing block's size is <a>indefinite</a>,
+	the result is the same as a <a>main size</a> of <a value for=width>auto</a>
+	(which in this case is treated as ''content'').
+	As another corollary,
+	'flex-basis' determines the size of the content box,
+	unless otherwise specified
+	such as by 'box-sizing' [[CSS3UI]].
 
 <h2 id='alignment'>
 Alignment</h2>