fix($default-theme): remove custom layout legacy. (close: #935)

Author: ulivz

packages/@vuepress/theme-default/layouts/Layout.vue

@@ -29,14 +29,7 @@
       />
     </Sidebar>
 
-    <div
-      class="custom-layout"
-      v-if="$page.frontmatter.layout"
-    >
-      <component :is="$page.frontmatter.layout"/>
-    </div>
-
-    <Home v-else-if="$page.frontmatter.home"/>
+    <Home v-if="$page.frontmatter.home"/>
 
     <Page
       v-else

packages/@vuepress/theme-default/styles/theme.styl

@@ -162,9 +162,6 @@ th, td
   border 1px solid #dfe2e5
   padding .6em 1em
 
-.custom-layout
-  padding-top $navbarHeight
-
 .theme-container
   &.sidebar-open
     .sidebar-mask
@@ -175,8 +172,6 @@ th, td
         padding-top 0
     .sidebar
       top 0
-    .custom-layout
-      padding-top 0
 
 
 @media (min-width: ($MQMobile + 1px))