ChangeLog, release notes for json v2

ChangeLog

@@ -1,5 +1,10 @@
 2022-05-30  Jay Berkenbilt  <ejb@ql.org>
 
+        * qpdf JSON is now at version 2. New command-line arguments:
+        --json-output, --json-input, --update-from-json. New methods
+        QPDF::writeJSON, QPDF::createFromJSON, QPDF::updateFromJSON. For
+        details, see the "qpdf JSON" chapter of the manual.
+
         * When showing encryption data in json output, when the user
         password was recovered with by the owner password and the
         specified password does not match the user password, reveal the

manual/release-notes.rst

@@ -18,6 +18,25 @@ For a detailed list of changes, please see the file
       this can be turned off by following the migration steps outlined
       in the manual.
 
+  - qpdf JSON version 2
+
+    - qpdf's JSON output mode is now at version 2. This fixes several
+      flaws with version 1. Version 2 JSON output is unambiguous and
+      complete, and bidrectional conversion between JSON and PDF is
+      supported. Command-line options and library API are available
+      for creating JSON from PDF, creating PDF from JSON and updating
+      existing PDF at the object level from JSON.
+
+    - New command-line arguments: :qpdf:ref:`--json-output`,
+      :qpdf:ref:`--json-input`, :qpdf:ref:`--update-from-json`
+
+    - New C++ API calls: ``QPDF::writeJSON``,
+      ``QPDF::createFromJSON``, ``QPDF::updateFromJSON``
+
+    - Complete documentation can be found at :ref:`json`. A
+      comprehensive list of changes from version 1 to version 2 can be
+      found at :ref:`json-v2-changes`.
+
   - Build replaced with cmake
 
     - The old autoconf-based build has been replaced with CMake. Version