[css-sizing-3] Add note about flex-basis so implementers don't forget. Move note out of the way so we don't have so many notes all in a row.

Author: fantasai

css-sizing-3/Overview.bs

@@ -44,6 +44,9 @@ Introduction</h2>
 		and some new keywords for the 'width' and 'height' properties
 		to allow authors to assign elements the dimensions resulting from these size calculations.
 
+
+		Issue: This spec needs illustrations! See
+
 <h3 id="placement">
 Module interactions</h3>
 
@@ -327,11 +330,8 @@ New Keywords for 'width' and 'height'</h3>
 	to better work out the implications in situations with
 	<a>indefinite</a> <a>available space</a>.
 
-	Note: To size an element such that it avoids overlapping sibling floats,
-	make sure it's a <a>formatting context</a> root.
-	For some layout modes, such as Grid and Flexbox,
-	this is true automatically.
-	For Block layout, this means using ''display: flow-root;''.
+	Note: The 'flex-basis' property hereby also gains these new keywords,
+	as its values are defined by reference to <'width'>.
 
 <h4 id="behave-auto">
 “Behaving as ''width/auto''”</h4>
@@ -359,14 +359,20 @@ New Keywords for 'width' and 'height'</h3>
 	and reported to the CSSWG for updating.
 
 <h3 id='the-contain-floats-value'>
-Containing Floats</h3>
+Containing or Excluding Floats</h3>
 
 	Note: To ensure that a container sizes itself to contain any descendant floats,
 	make sure it's a <a>formatting context</a> root.
 	For some layout modes, such as Grid and Flexbox,
 	this is true automatically.
 	For Block layout, this means using ''display: flow-root;''.
 
+	Note: To size an element such that it avoids overlapping sibling floats,
+	make sure it's a <a>formatting context</a> root.
+	For some layout modes, such as Grid and Flexbox,
+	this is true automatically.
+	For Block layout, this means using ''display: flow-root;''.
+
 <h3 id='column-sizing'>
 Column Sizing Keywords</h3>