[css-flexbox] Remove all the propdef lines that don't apply to shorthands.

Author: tabatkins

css-flexbox/Overview.bs

@@ -1119,13 +1119,6 @@ Flex Direction and Wrap: the 'flex-flow' shorthand</h3>
 	<pre class='propdef shorthand'>
 	Name: flex-flow
 	Value: <'flex-direction'> || <'flex-wrap'>
-	Initial: row nowrap
-	Applies to: <a>flex containers</a>
-	Inherited: no
-	Percentages: n/a
-	Computed value: specified value
-	Media: visual
-	Animation type: discrete
 	</pre>
 
 	The 'flex-flow' property is a shorthand for setting the 'flex-direction' and 'flex-wrap' properties,
@@ -1491,11 +1484,6 @@ The 'flex' Shorthand</h3>
 	<pre class='propdef shorthand'>
 	Name: flex
 	Value: none | [ <<'flex-grow'>> <<'flex-shrink'>>? || <<'flex-basis'>> ]
-	Initial: 1 0 auto
-	Applies to: <a>flex items</a>
-	Inherited: no
-	Media: visual
-	Canonical order: per grammar
 	</pre>
 
 	The 'flex' property specifies the components of a <dfn>flexible length</dfn>: