Update NEWS for 0.3.0.

* NEWS (release 0.3.0): New section.

NEWS

@@ -1,6 +1,32 @@
 All The Latest Gash News
 ************************
 
+Noteworthy changes in release 0.3.0 (2022-02-11)
+================================================
+
+New features
+
+  - Arithmetic expansion.
+  - Simple asynchronous commands.
+  - A language specification is now provided, allowing you to use the
+    evaluator from the Guile REPL by typing ",L sh".
+  - Redirects now honor the 'noclobber' option.
+  - The 'wait' built-in.
+  - The 'umask' built-in can now display the current umask.
+
+Bug fixes
+
+  - An empty command will now reset the status.
+  - The 'read-sh' procedure now reads from 'current-input-port' by
+    default (before it used 'current-output-port').
+
+Miscellaneous improvements
+
+  - Various performance improvements.
+  - Word expansion has been split into two steps, paving the way for a
+    compiler.
+  - Guile 3.0 is now explicitly supported.
+
 Noteworthy changes in release 0.2.0 (2019-12-15)
 ================================================