Add release notes for a 0.23.0 release.
--------------------------------------------------------------------------------
+## 0.23.0
+
+Released 2021-02-16.
+
+### Added
+
+* Support for limiting WebAssembly execution with fuel was added, including
+ support in the C API.
+ [#2611](https://github.com/bytecodealliance/wasmtime/pull/2611)
+ [#2643](https://github.com/bytecodealliance/wasmtime/pull/2643)
+* Wasmtime now has more knobs for limiting memory and table allocations
+ [#2617](https://github.com/bytecodealliance/wasmtime/pull/2617)
+* Added a method to share `Config` across machines
+ [#2608](https://github.com/bytecodealliance/wasmtime/pull/2608)
+* Added a safe memory read/write API
+ [#2528](https://github.com/bytecodealliance/wasmtime/pull/2528)
+* Added support for the experimental wasi-crypto APIs
+ [#2597](https://github.com/bytecodealliance/wasmtime/pull/2597)
+* Added an instance limit to `Config`
+ [#2593](https://github.com/bytecodealliance/wasmtime/pull/2593)
+* Implemented module-linking's outer module aliases
+ [#2590](https://github.com/bytecodealliance/wasmtime/pull/2590)
+* Cranelift now supports 128-bit operations
+ [#2539](https://github.com/bytecodealliance/wasmtime/pull/2539)
+* Cranelift now has detailed debug-info (DWARF) support in new backends (initially x64).
+ [#2565](https://github.com/bytecodealliance/wasmtime/pull/2565)
+* Cranelift now uses the `POPCNT`, `TZCNT`, and `LZCNT`, as well as SSE 4.1
+ rounding instructions on x64 when available.
+* Cranelift now uses the `CNT`, instruction on aarch64 when available.
+
+### Changed
+
+* A new WASI implementation built on the new
+ [`cap-std`](https://github.com/bytecodealliance/cap-std) crate was added,
+ replacing the previous implementation. This brings improved robustness,
+ portability, and performance.
+* The WebAssembly C API is updated, with a few minor API changes
+ [#2579](https://github.com/bytecodealliance/wasmtime/pull/2579)
+
+### Fixed
+
+* Fixed a panic in WASI `fd_readdir` on large directories
+ [#2620](https://github.com/bytecodealliance/wasmtime/pull/2620)
+* Fixed a memory leak with command modules
+ [#2017](https://github.com/bytecodealliance/wasmtime/pull/2017)
+
+--------------------------------------------------------------------------------
+
## 0.22.0
Released 2021-01-07.
