fixed changelog to unreleased

Author: alexismarquet

CHANGELOG.md

@@ -7,14 +7,15 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+- Support for device.x generation for riscv targets and `__EXTERNAL_INTERRUPTS` vector table
+
 ## [v0.19.0] - 2021-05-26
 
 ### Added
 
 - MSP430 API for atomically changing register bits, gated behind the `--nightly` flag
 - New SVD test for `msp430fr2355`
 - Option `-o`(`--output-path`) let you specify output directory path
-- Support for device.x generation for riscv targets and `__EXTERNAL_INTERRUPTS` vector table
 
 ### Changed