[css-timing-1] Add syntax to section headings

This covers the first part of w3c#2027.

Author: birtles

css-timing-1/Overview.bs

@@ -88,8 +88,8 @@ This specification defines four types of timing functions whose definitions
 follow.
 
 
-The linear timing function {#linear-timing-function-section}
---------------------------
+The linear timing function: ''linear'' {#linear-timing-function-section}
+------------------------------------------------------------------------
 
 The <dfn export>linear timing function</dfn> is an identity function
 meaning that its [=output progress value=] is equal to the
@@ -99,7 +99,7 @@ The syntax for the [=linear timing function=] is simply the
 <dfn dfn-type=value for=single-timing-function>linear</dfn> keyword.
 
 
-Cubic B&eacute;zier timing functions {#cubic-bezier-timing-functions}
+Cubic B&eacute;zier timing functions: ''ease'', ''ease-in'', ''ease-out'', ''ease-in-out'', ''cubic-bezier()'' {#cubic-bezier-timing-functions}
 ---------------------------------------------------------------------
 
 A <dfn export>cubic B&eacute;zier timing function</dfn> is a type of [=timing
@@ -196,8 +196,8 @@ The keyword values listed above are illustrated below.
 </figure>
 
 
-Step timing functions {#step-timing-functions}
----------------------
+Step timing functions: ''step-start'', ''step-end'', ''steps()'' {#step-timing-functions}
+----------------------------------------------------------------
 
 A <dfn>step timing function</dfn> is a type of <a>timing function</a>
 that divides the input time into a specified number of intervals that
@@ -324,8 +324,8 @@ The meaning of each value is as follows:
 
 </dl>
 
-Frames timing functions {#frames-timing-functions}
------------------------
+Frames timing functions: ''frames()'' {#frames-timing-functions}
+----------------------------------------------------------------
 
 A <dfn>frames timing function</dfn> is a type of <a>timing function</a>
 that divides the input time into a specified number of intervals of equal