feat: support dir in frontmatter (#3353)

Co-authored-by: Divyansh Singh <40380293+brc-dd@users.noreply.github.com>

src/client/app/data.ts

@@ -89,7 +89,7 @@ export function initData(route: Route): VitePressData {
     frontmatter: computed(() => route.data.frontmatter),
     params: computed(() => route.data.params),
     lang: computed(() => site.value.lang),
-    dir: computed(() => site.value.dir),
+    dir: computed(() => route.data.frontmatter.dir || site.value.dir || 'ltr'),
     localeIndex: computed(() => site.value.localeIndex || 'root'),
     title: computed(() => {
       return createTitle(site.value, route.data)

src/client/theme-default/styles/base.css

@@ -39,7 +39,6 @@ body {
   font-weight: 400;
   color: var(--vp-c-text-1);
   background-color: var(--vp-c-bg);
-  direction: ltr;
   font-synthesis: style;
   text-rendering: optimizeLegibility;
   -webkit-font-smoothing: antialiased;