fix: missing sidebar button on a mobile homepage

fix #1355

Author: sinchang

Diff for: lib/default-theme/Layout.vue

@@ -98,13 +98,14 @@ export default {
       const { frontmatter } = this.$page
       return (
         !frontmatter.layout &&
-        !frontmatter.home &&
         frontmatter.sidebar !== false &&
-        this.sidebarItems.length
+        (this.sidebarItems.length || frontmatter.home)
       )
     },
 
     sidebarItems () {
+      const { frontmatter } = this.$page
+      if (frontmatter.home) return []
       return resolveSidebarItems(
         this.$page,
         this.$route,