Prepare release 0.8.1

Refs: #5250
Change-Id: I99931c1300cd752554aea764e9688d027b5de29e
diff --git a/docs/release-notes/release-notes-0.8.1.rst b/docs/release-notes/release-notes-0.8.1.rst
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+ndn-cxx version 0.8.1
+---------------------
+
+Release date: December 31, 2022
+
+.. note::
+   This is the last release of ndn-cxx to support the C++14 standard.
+   Future versions will require C++17 to build.
+
+Important changes and new features
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+- The minimum build requirements have been increased as follows:
+
+  - Either GCC >= 7.4.0 or Clang >= 6.0 is required on Linux
+  - On macOS, Xcode 11.3 or later is recommended; older versions may still work but are not
+    officially supported
+  - Boost >= 1.65.1 and OpenSSL >= 1.1.1 are required on all platforms
+  - Sphinx 4.0 or later is required to build the documentation
+
+- CentOS Stream 9 is now officially supported; CentOS 8 has been dropped (:issue:`5181`)
+
+- macOS 12 (Monterey) and 13 (Ventura) running on arm64 are now officially supported
+  (:issue:`5135`)
+
+- Add the initial version of a :ndn-cxx:`Segmenter` API that applications can use to simplify
+  the process of chunking a large object into multiple signed Data packets (:issue:`5247`)
+
+- Add ``KeyChain::makeCertificate()`` to simplify the creation of certificates
+
+- Put the full certificate name in the ``KeyLocator`` field, instead of just the key name
+  (:issue:`5112`)
+
+- NFD management commands sent by :ndn-cxx:`nfd::Controller` now use the `new signed Interest
+  format <https://named-data.net/doc/NDN-packet-spec/0.3/signed-interest.html>`__ (:issue:`4804`)
+
+Improvements and bug fixes
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+- Several enhancements and cleanups in :ndn-cxx:`Name` and :ndn-cxx:`Component` to make
+  the API more consistent and simpler to use (:issue:`5186`)
+
+- Various improvements in the validation framework and policies
+
+  - Avoid redundant TLV decoding during Interest validation
+  - Fix validation of signed Interests with malformed ``InterestSignatureInfo``
+  - More accurate validation error codes are returned in several cases
+  - Rename ``ValidationError::NO_SIGNATURE`` to ``MALFORMED_SIGNATURE``
+
+- Optimize parsing of PIB and TPM locators in :ndn-cxx:`KeyChain`
+
+- Major cleanup and modernization of PIB implementation
+
+- Gracefully handle invalid or unsupported public keys stored in the PIB
+
+- Fix OpenSSL 3.0 deprecation warnings in private key generation routines (:issue:`5154`)
+
+- Change ``Certificate::getPublicKey()`` to return a ``span``
+
+- Make :ndn-cxx:`Block` convertible to ``span<const uint8_t>``
+
+- Avoid assertion failure in :ndn-cxx:`OBufferStream` under certain conditions (:issue:`5240`)
+
+- Allow customizing the FaceId in :ndn-cxx:`DummyClientFace` (:issue:`5011`)
+
+- Improve pretty-printing of certificates, e.g., in ``ndnsec list`` and ``ndnsec cert-dump``
+
+- Relax restrictions on KeyId component type in ``ndnsec key-gen``
+
+- Fix handling of ``--without-osx-keychain`` configure option (:issue:`3338`)
+
+- Stop using the ``gold`` linker on Linux; prefer instead linking with ``lld`` if installed
+
+- Update waf build system to version 2.0.24
+
+- Various documentation improvements
+
+Deprecations
+^^^^^^^^^^^^
+
+- ``Name::append()`` overloads and :ndn-cxx:`Component` constructors that take a
+  ``const uint8_t*``. Use the ``span``-based overloads instead.
+
+- ``Component::fromImplicitSha256Digest()`` and ``Component::fromParametersSha256Digest()``.
+  Use one of the constructors directly instead.
+
+Removals
+^^^^^^^^
+
+- Obsolete TLV-TYPE definitions
+
+- Many previously deprecated functions that take raw byte buffers as ``uint8_t*`` + ``size_t``,
+  replaced by equivalent functions that take a ``span``. These include ``Data::setContent()``,
+  ``Interest::setApplicationParameters()``, ``Block::fromBuffer()``, ``verifySignature()``,
+  ``PublicKey::loadPkcs8()``, ``transform::bufferSource()``, ``random::generateSecureBytes()``,
+  ``printHex()``, ``toHex()``, and so on.
+
+- Previously deprecated ``Name::append(Block)`` overload
+
+- Previously deprecated ``Interest::setDefaultCanBePrefix()``
+
+- ``ndn::any`` and related functionality