Prepare release 0.3.0

Change-Id: I193b7cde69fcab7d2757a7823a727121572b51ad
diff --git a/docs/release-notes/release-notes-0.3.0.rst b/docs/release-notes/release-notes-0.3.0.rst
new file mode 100644
index 0000000..f5d2e10
--- /dev/null
+++ b/docs/release-notes/release-notes-0.3.0.rst
@@ -0,0 +1,25 @@
+PSync version 0.3.0
+-------------------
+
+The build requirements have been increased to require Clang >= 4.0, Xcode >= 9.0, and Python >= 3.6.
+Meanwhile, it is *recommended* to use GCC >= 7.4.0 and Boost >= 1.65.1.
+This effectively drops official support for Ubuntu 16.04 when using distribution-provided Boost
+packages -- PSync may still work on this platform, but we provide no official support for it.
+
+We have taken some steps to be endian safe but PSync is not completely endian safe yet (:issue:`4818`)
+
+New features
+^^^^^^^^^^^^
+
+- **breaking** Consumer: change hello data callback to include sequence number (:issue:`5122`)
+- Support various compression schemes for compressing IBF and Sync Data (:issue:`5061`)
+
+Improvements and bug fixes
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+- **breaking** IBLT: make encoding endian safe (:issue:`5076`)
+- Reset cached wire encoding after adding names (:issue:`5083`)
+- Consumer reacts faster on sync Interest timeout (:issue:`5124`)
+- Move private classes and functions to ``psync::detail`` namespace
+- Improved unit tests
+