fix errant slashes in CHANGELOG, resolves #63

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## \[Unreleased\]
+## [Unreleased]
 
 ### Added
 
@@ -28,4 +28,4 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 See the [stac-spec CHANGELOG](https://github.com/radiantearth/stac-spec/blob/v0.9.0/CHANGELOG.md)
 for STAC API releases prior to or equal to version 0.9.0.
 
-\[Unreleased\]: <https://github.com/radiantearth/stac-api-spec/compare/master...dev>
+[Unreleased]: <https://github.com/radiantearth/stac-api-spec/compare/master...dev>