chore: modify configuration for pagination plugin (#1667)

Author: thinkasany

main.js

@@ -77,8 +77,14 @@ window.$docsify = {
         },
     },
     pagination: {
-        previousText: isEn() ? 'PREVIOUS' : '上一题',
-        nextText: isEn() ? 'NEXT' : '下一题',
+        previousText: {
+            '/README_EN': 'PREVIOUS',
+            '/': '上一题',
+        },
+        nextText: {
+            '/README_EN': 'NEXT',
+            '/': '下一题',
+        },
         crossChapter: true,
         crossChapterText: true,
     },