docs: minor fix emojis link (vuejs#2520)

Small fix in the markdown

Author: gauthamzz

packages/docs/docs/guide/markdown.md

@@ -99,7 +99,7 @@ For more details, see [Frontmatter](./frontmatter.md).
 
 :tada: :100:
 
-A [list of all emojis] (https://github.com/markdown-it/markdown-it-emoji/blob/master/lib/data/full.json) is available.
+A [list of all emojis](https://github.com/markdown-it/markdown-it-emoji/blob/master/lib/data/full.json) is available.
 
 ## Table of Contents