Problem: not clear what changed in 0.2.0

Solution: add release notes

(It'd be nice to prepare a changelog soon!)

RELEASE_NOTES.md

@@ -0,0 +1,66 @@
+# 0.2.0
+
+In this release, the most notable change was splitting of PumpkinDB into
+multiple crates. This enables PumpkinDB users to build custom systems
+(embedded and client-server ones) that use PumpkinDB as an engine. Also,
+pumpkinscript and pumpkindb_client crates allow building Rust applications
+that use PumpkinDB as remote clients. pumpkindb_mio_server crate simplifies
+developing custom PumpkinDB server builds.
+
+A confusing "word" term has been changed to "instruction" to provide a clearer
+indication of the concept behind it.
+
+We've also introduced more conventions around numbers (especially
+signed and unsigned sized integers, as well as floats) and added respective
+instructions to the library.
+
+Initial UUID support has been added. Cursor API surface has been reduced and
+is much easier to comprehend now.
+
+Internally, a lot has changed. A new messaging system (it is now available
+not only through the server component, but pumpkindb_engine as well). Dispatcher
+trait allows defining custom sets of instruction "modules" and is flexible enough
+to support both static and dynamic dispatching.
+
+And, of course, a number of bugs has been spotted and some of them were even
+fixed. We've also optimized a number of things and found out that there's a lot
+more to optimize in the upcoming versions!
+
+This is the first release with published [library crates on crates.io](https://crates.io/search?q=pumpkindb)
+
+Also, this release includes statically built versions of PumpkinDB server
+and terminal for Linux (using musl). This is an experimental build as in
+the future we might need to depend on some dynamically libraries. 
+
+New contributors: alex, Christoph Herzog, Guillaume Gauvrit, Matteo Semenzato
+and Stuart Hinson.
+
+Thank you!
+
+SHA-256 checksums:
+
+| File | Checksum |
+|------|----------|
+| pumpkindb-v0.2.0-x86_64-apple-darwin.tar.gz | f7e81dfa0bfc02de31b4bd70c5b6a13e95a44550d33d53a77179f5c23a9efde4 |
+| pumpkindb-v0.2.0-x86_64-pc-windows-msvc.zip | cf4b0fb7e893fdcd4fc7881b01e7c4bf045594e85bdd73cc88d2fec8ac2418a1  |
+| pumpkindb-v0.2.0-x86_64-unknown-linux-gnu.tar.gz | efcca81f4b482d6a69bfe08f935d2da61c8f7e2262798dcd93a656aeb8c58e15 |
+| pumpkindb-v0.2.0-x86_64-unknown-linux-musl.tar.gz | 4dc32dbf05dbe0df727128c7455c5482d3366ebf1a32f7308d22120a53c67388 |
+
+# 0.1.0
+
+This is PumpkinDB's first release (ever!), the intention of which is to finally
+provide some binaries to those who want to play with PumpkinDB but can't be
+bothered to install Rust and switch to nightly builds just yet!
+
+Don't expect it to be very stable or feature-complete. Those were the non-goals
+this time around!
+
+We'd really like you to try it out and let us know what you think about it!
+
+SHA-256 checksums:
+
+| File | Checksum |
+|------|----------|
+| pumpkindb-v0.1.0-x86_64-apple-darwin.tar.gz | 0c4bf2f56bee2139d3a0616be882df828fe881abd45a8176d076547fb9da7ea8 |
+| pumpkindb-v0.1.0-x86_64-pc-windows-msvc.zip | f8d0f48486ef790ee36620823503aaefaa6a4eb9fef856b136e948791318d2d4 |
+| pumpkindb-v0.1.0-x86_64-unknown-linux-gnu.tar.gz | 5d1355cf88a7b691c12ad8ec2bca3cbf783e42cde48a975b059890ed88496fad |