docs: fix typo

ulivz · web-flow · commit 9c354beefbb5 · 2019-03-13T23:30:50.000+08:00
diff --git a/packages/docs/docs/theme/writing-a-theme.md b/packages/docs/docs/theme/writing-a-theme.md
@@ -40,7 +40,7 @@ theme
 ├── `components`
 │   └── xxx.vue
 ├── `layouts`
-│   ├── Layout.vue _(**必要的**)_
+│   ├── Layout.vue _(**Mandatory**)_
 │   └── 404.vue
 ├── `styles`
 │   ├── index.styl
