Fixed CHANGELOG.md formatting (#1707)

This fixes some formatting issues in the changelog.

CHANGELOG.md

@@ -15,7 +15,7 @@
 * __Kotlin__
 	* Add keywords of Kotlin and modify it's number pattern. ([#1389](https://github.com/PrismJS/prism/issues/1389)) [[`1bf73b0`](https://github.com/PrismJS/prism/commit/1bf73b0)]
 	* Add `typealias` keyword ([#1437](https://github.com/PrismJS/prism/issues/1437)) [[`a21fdee`](https://github.com/PrismJS/prism/commit/a21fdee)]
-* __JavaScript
+* __JavaScript__
 	* Improve Regexp pattern [[`5b043cf`](https://github.com/PrismJS/prism/commit/5b043cf)]
 	* Add support for one level of nesting inside template strings. Fix [#1397](https://github.com/PrismJS/prism/issues/1397) [[`db2d0eb`](https://github.com/PrismJS/prism/commit/db2d0eb)]
 * __Elixir__
@@ -686,13 +686,13 @@
 	* Make CSS strings greedy. Fix [#1013](https://github.com/PrismJS/prism/issues/1013). [[`e57e26d`](https://github.com/PrismJS/prism/commit/e57e26d)]
 * __CSS Extras__:
 	* Match attribute inside selectors [[`13fed76`](https://github.com/PrismJS/prism/commit/13fed76)]
-* _Groovy__:
+* __Groovy__:
 	* Fix order of decoding entities in groovy. Fixes [#1049](https://github.com/PrismJS/prism/issues/1049) ([#1050](https://github.com/PrismJS/prism/issues/1050)) [[`d75da8e`](https://github.com/PrismJS/prism/commit/d75da8e)]
 * __Ini__:
 	* Remove important token in ini definition ([#1047](https://github.com/PrismJS/prism/issues/1047)) [[`fe8ad8b`](https://github.com/PrismJS/prism/commit/fe8ad8b)]
 * __JavaScript__:
 	* Add exponentiation & spread/rest operator ([#991](https://github.com/PrismJS/prism/issues/991)) [[`b2de65a`](https://github.com/PrismJS/prism/commit/b2de65a), [`268d01e`](https://github.com/PrismJS/prism/commit/268d01e)]
-* __JSON_:
+* __JSON__:
 	* JSON: Fixed issues with properties and strings + added tests. Fix [#1025](https://github.com/PrismJS/prism/issues/1025) [[`25a541d`](https://github.com/PrismJS/prism/commit/25a541d)]
 * __Markup__:
 	* Allow for dots in Markup tag names, but not in HTML tags included in Textile. Fixes [#888](https://github.com/PrismJS/prism/issues/888). [[`31ea66b`](https://github.com/PrismJS/prism/commit/31ea66b)]