fix the error when using 'hexo g' in v2.8.1 by adding double quotes i…

…n yml files

error log:
reason: 'incomplete explicit mapping pair; a key node is missed', ....

languages/default.yml

@@ -1,18 +1,18 @@
 categories: Categories
 search: Search
 tags: Tags
-tagcloud: Tag Cloud
+tagcloud: "Tag Cloud"
 prev: Prev
 next: Next
 comment: Comments
 contents: Contents
 archive_a: Archives
-archive_b: Archives: %s
-page: Page %d
-recent_posts: Recent Posts
+archive_b: "Archives: %s"
+page: "Page %d"
+recent_posts: "Recent Posts"
 menu: Menu
 links: Links
 rss: RSS
-showsidebar: Show Sidebar
-hidesidebar: Hide Sidebar
-updated: Updated
+showsidebar: "Show Sidebar"
+hidesidebar: "Hide Sidebar"
+updated: Updated