[css-variables-2] Replace the Changes section, and credit @jonathantneal

Author: tabatkins

css-variables-2/Overview.bs

@@ -1412,54 +1412,10 @@ Serializing Custom Properties</h3>
 <h2 id='changes'>
 Changes</h2>
 
-<h3 id='changes-20220616'>
-Changes Since the 16 June CR Snapshot</h3>
-
-<h3 id='changes-20211111'>
-Changes Since the 11 November 2021 CR Draft</h3>
-
-	* Clarified that custom properties apply all pseudo-elements (including those with restricted property lists)
-	* Added example to illustrate issues with combining characters, ligatures, etc
-	* Strengthened wording around similar-appearing variable names that use distinct codepoint sequences
-	* Clarified an example by using more visualy distinct languages as examples (English and Greek)
-	* Split Security and Privacy into separate sections
-
-<h3 id='changes-20151203'>
-Changes Since the 03 December 2015 CR</h3>
-
-	* Now that [[css-syntax-3]] auto-trims whitespace from declaration values,
-		made <<declaration-value>> optional in the custom property grammar,
-		so that empty variables are still allowed.
-		(<a href="https://github.com/w3c/csswg-drafts/issues/774#issuecomment-434571254">Issue 774</a>)
-	* Similarly, made empty fallbacks valid in ''var()''.
-	* The '-' property is reserved for future use by CSS.
-	* Added concept of "animation-tainted",
-		to prevent non-animatable properties
-		from using a variable to smuggle in some animatability.
-	* Defined the [=guaranteed-invalid value=]
-		to make the initial value of custom properties
-		and the result of cycles or substitution failure
-		more straightforward,
-		and allow failure to propagate thru substitutions
-		until finally intercepted by a fallback.
-	* Defined that cycles trigger [=invalid at computed-value time=] behavior.
-	* Allowed variables to resolve to a CSS-wide keyword
-		(only possible by providing it as a fallback).
-	* Clarified that [=registered custom properties=] act like non-custom properties
-		when they're [=invalid at computed-value time=].
-	* Made longhands with ''var()''s also trigger their shorthands to be unserializable,
-		like longhands with pending-substitution values already did.
-	* Required UAs to defend against exponential substitution attacks.
-	* Defined how to serialize the <em>values</em> of custom properties
-		(previously, only the property name's serialization was specified).
-
-<h3 id='changes-20140506'>
-Changes since the May 6 2014 Last Call Working Draft</h2>
-
-	* Serialization of longhands when shorthand uses a variable was defined.
-	* Link to DOM's definition of "case-sensitive".
-	* Added example of using variables with '':lang()'' to do simple i18n.
-	* Clarified that usage of ''var()'' in a custom property must be valid per the ''var()'' grammar.
+<h3 id='changes-v1'>
+Changes Since Variables 1</h3>
+
+	* Added [=variable unit references=].
 
 
 <h2 id="acks">
@@ -1472,6 +1428,7 @@ Acknowledgments</h2>
 	Brian Kardell,
 	David Baron,
 	François Remy,
+	Jonathan Neal,
 	Roland Steiner,
 	and Shane Stephens.