Improve "codegen 1.1" entry

"version 1.1 of #5137" is not meaningful to users, only as an internal
project milestone. Explain what this means from a user's point of view.

Announce the requirement for jsonschema in the proper section, which is
"Requirement changes". Mention jinja2 and basic.requirements.txt which
had not previously been explicitly mentioned in the changelog.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/ChangeLog.d/psa_crypto_code_gen_1_1.txt b/ChangeLog.d/psa_crypto_code_gen_1_1.txt
index 2c18e6f..e10a81c 100644
--- a/ChangeLog.d/psa_crypto_code_gen_1_1.txt
+++ b/ChangeLog.d/psa_crypto_code_gen_1_1.txt
@@ -1,6 +1,13 @@
 Features
-    * Brought in PSA code geneneration JSON driver list.
-      Added auto generated templating support for key management.
-      Added Support for transparent and opaque keys (import/export/copy).
-      Included some general JSON validation for the given entry points.
-      Addresses version 1.1 of #5137.
+    * The PSA driver wrapper generator generate_driver_wrappers.py now
+      supports a subset of the driver description language, including
+      the following entry points: import_key, export_key, export_public_key,
+      get_builtin_key, copy_key.
+
+Requirement changes
+   * When building with PSA drivers using generate_driver_wrappers.py, or
+     when building the library from the development branch rather than
+     from a release, the Python module jsonschema is now necessary, in
+     addition to jinja2. The official list of required Python modules is
+     maintained in scripts/basic.requirements.txt and may change again
+     in the future.