feat(theme): allow customizing prev/next text from config file

closes #1373

src/client/theme-default/composables/prev-next.ts

@@ -31,7 +31,9 @@ export function usePrevNext() {
                 ? frontmatter.value.prev
                 : typeof frontmatter.value.prev === 'object'
                 ? frontmatter.value.prev.text
-                : undefined) ?? candidates[index - 1]?.text,
+                : undefined) ??
+              candidates[index - 1]?.docFooterText ??
+              candidates[index - 1]?.text,
             link:
               (typeof frontmatter.value.prev === 'object'
                 ? frontmatter.value.prev.link
@@ -45,7 +47,9 @@ export function usePrevNext() {
                 ? frontmatter.value.next
                 : typeof frontmatter.value.next === 'object'
                 ? frontmatter.value.next.text
-                : undefined) ?? candidates[index + 1]?.text,
+                : undefined) ??
+              candidates[index + 1]?.docFooterText ??
+              candidates[index + 1]?.text,
             link:
               (typeof frontmatter.value.next === 'object'
                 ? frontmatter.value.next.link

src/client/theme-default/support/sidebar.ts

@@ -5,6 +5,7 @@ import { isActive } from '../../shared'
 export interface SidebarLink {
   text: string
   link: string
+  docFooterText?: string
 }
 
 type SidebarItem = DefaultTheme.SidebarItem
@@ -71,7 +72,11 @@ export function getFlatSideBarLinks(sidebar: SidebarItem[]): SidebarLink[] {
   function recursivelyExtractLinks(items: SidebarItem[]) {
     for (const item of items) {
       if (item.text && item.link) {
-        links.push({ text: item.text, link: item.link })
+        links.push({
+          text: item.text,
+          link: item.link,
+          docFooterText: item.docFooterText
+        })
       }
 
       if (item.items) {

types/default-theme.d.ts

@@ -229,6 +229,11 @@ export namespace DefaultTheme {
      * Base path for the children items.
      */
     base?: string
+
+    /**
+     * Customize text that appears on the footer of previous/next page.
+     */
+    docFooterText?: string
   }
 
   /**