optimize export sync plans, and clear too many sync plans

src/langs/zh_tw.json

@@ -38,7 +38,9 @@
   "protocol_onedrive_connect_unknown": "不知道如何處理此 callback：{{params}}",
   "command_startsync": "開始同步（start sync）",
   "command_drynrun": "開始同步（空跑模式）（start sync (dry run only)）",
-  "command_exportsyncplans_json": "匯出同步計劃為 json 格式（export sync plans in json format）",
+  "command_exportsyncplans_1": "匯出同步計劃（最近 1 次）（export sync plans (latest 1)）",
+  "command_exportsyncplans_5": "匯出同步計劃（最近 5 次）（export sync plans (latest 5)）",
+  "command_exportsyncplans_all": "匯出同步計劃（所有）（export sync plans (all)）",
   "command_exportlogsindb": "從資料庫匯出終端日誌（export logs saved in db）",
 
   "statusbar_time_years": "{{time}} 年前同步",
@@ -291,7 +293,9 @@
   "settings_viewconsolelog_desc": "電腦上，輸入“ctrl+shift+i”或“cmd+shift+i”來檢視終端輸出。手機上，安裝第三方外掛 <a href='https://obsidian.md/plugins?search=Logstravaganza'>Logstravaganza</a> 來匯出終端輸出到一篇筆記上。",
   "settings_syncplans": "匯出同步計劃",
   "settings_syncplans_desc": "每次您啟動同步，並在實際上傳下載前，外掛會生成同步計劃。它可以使您知道每次同步發生了什麼。點選按鈕可以匯出同步計劃。",
-  "settings_syncplans_button_json": "匯出",
+  "settings_syncplans_button_1": "匯出最近 1 次",
+  "settings_syncplans_button_5": "匯出最近 5 次",
+  "settings_syncplans_button_all": "匯出所有",
   "settings_syncplans_notice": "同步計劃已匯出",
   "settings_delsyncplans": "刪除資料庫裡的同步計劃歷史",
   "settings_delsyncplans_desc": "刪除資料庫裡的同步計劃歷史。",