Updated doc

CHANGES.md

@@ -0,0 +1,19 @@
+This file compiles the list of functional changes for each version. For backward-incompatible API changes, see `UPGRADING.md`.
+
+
+# 2.0.0
+
+ - The final expression does not use a non-capturing group for its first set of alternations. The `s9e\RegexpBuilder\Builder::$standalone` property can be used to control this behaviour.
+     - Old: `(?:aa|bb(?:cc|dd))
+     - New: `aa|bb(?:cc|dd)`
+
+ - The Java output uses `\uHHHH` instead of `\u{HHHH}`.
+
+ - Expressions created from meta-characters are moved to the end of a group.
+     - Old: `(?:.*|x)`
+     - New: `(?:x|.*)`
+
+ - Strings are sorted *after* surrogate pairs are created.
+     - Old: `\uD83C\uDD90(?:\uFE0F|\uD83C[\uDFFB-\uDFFF])?`
+     - New: `\uD83C\uDD90(?:\uD83C[\uDFFB-\uDFFF]|\uFE0F)?`
+

UPGRADING.md

@@ -26,7 +26,7 @@ $builder->input->useSurrogates = true;
 $builder->output->hexFormat = s9e\RegexpBuilder\Output\HexFormat::LowerCase;
 ```
 
-The same result can be obtained using a factory. Here we use the JavaScript factory:
+The same result can be obtained using a factory, which is the recommended way to create an instance. Here we use the JavaScript factory:
 
 ```php
 $builder = new s9e\RegexpBuilder\Factory\JavaScript::getBuilder();