chore: changelog typo (#988) [ci skip]

CHANGELOG.md

@@ -3,7 +3,7 @@
 
 ### Bug Fixes
 
-* **runtime-core:** fix user attched public instance properties that start with "$" ([d7ca1c5](https://github.com/vuejs/vue-next/commit/d7ca1c5c6e75648793d670299c9059b6db9b1715))
+* **runtime-core:** fix user attached public instance properties that start with "$" ([d7ca1c5](https://github.com/vuejs/vue-next/commit/d7ca1c5c6e75648793d670299c9059b6db9b1715))
 * **watch:** fix deep watchers on refs containing primitives ([#984](https://github.com/vuejs/vue-next/issues/984)) ([99fd158](https://github.com/vuejs/vue-next/commit/99fd158d090594a433b57d9ff9420f3aed48ad2d))