Update docs for UPDATE-FROM-5.1.X

docs/UPDATE-FROM-5.1.X.md

@@ -1,14 +1,14 @@
 <h1 align="center">Update from NexT v5.1.x</h1>
 
-NexT version 5 works fine at most cases, but for frequent users, you maybe need to upgrade version 5 to 6 to get features and supports in new [Theme-Next](https://github.com/theme-next/hexo-theme-next) repository.
+NexT version 5 works fine with Hexo 3, but for frequent users, you maybe need to upgrade version 5 to 7 to get features and supports in new [Theme-Next](https://github.com/theme-next/hexo-theme-next) repository.
 
-There are no hard breaking changes between 5.1.x and the latest version. It's change major version to 6 because:
+There are no hard breaking changes between 5.1.x and the latest version. It's change major version to 7 because:
 
 1. Main repo was rebased from [iissnan's](https://github.com/iissnan/hexo-theme-next) profile to [theme-next](https://github.com/theme-next) organization.
 2. Most libraries under the `next/source/lib` directory was moved out to [external repos under NexT organization](https://github.com/theme-next).
-3. 3rd-party plugin [`hexo-wordcount`](https://github.com/willin/hexo-wordcount) was replaced by [`hexo-symbols-count-time`](https://github.com/theme-next/hexo-symbols-count-time) because `hexo-symbols-count-time` no have any external nodejs dependencies, no have [language filter](https://github.com/willin/hexo-wordcount/issues/7) which causes better performance on speed at site generation.
+3. 3rd-party plugin [`hexo-wordcount`](https://github.com/willin/hexo-wordcount) was replaced by [`hexo-symbols-count-time`](https://github.com/theme-next/hexo-symbols-count-time) because `hexo-symbols-count-time` no have any external Node.js dependencies, no have [language filter](https://github.com/willin/hexo-wordcount/issues/7) which causes better performance on speed at site generation.
 
-So, i suggest to update from version 5 to version 6 in this way:
+So, we suggest to update from version 5 to version 7 in this way:
 
 1. You don't touch old `next` dir and just do some copies of NexT files:\
    1.1. `_config.yml` or `next.yml` (if you used [data-files](DATA-FILES.md)).\
@@ -22,5 +22,7 @@ So, i suggest to update from version 5 to version 6 in this way:
     Since v6.0.3, `zh-Hans` has been renamed to `zh-CN`: https://github.com/theme-next/hexo-theme-next/releases/tag/v6.0.3
 
     Users upgrading to v6.0.3 and later need to explicitly modify the `language` configuration in the Hexo main config file `_config.yml`, otherwise the language display is incorrect.
+5. Update Hexo and Hexo plugin
+    If after completing the above steps, an error occurs when executing `hexo s` or` hexo g`, it means that there may be a conflict between the old version of Hexo / Hexo plugin and the new version of the theme NexT. We recommend upgrading Hexo to versions 4.0 and higher and upgrading Hexo plugins to the latest version. You can run `npm outdated` to see all the upgradeable plugins.
 
 And how to enable 3rd-party libraries see [here](https://github.com/theme-next/hexo-theme-next/blob/master/docs/INSTALLATION.md#plugins).

docs/ru/UPDATE-FROM-5.1.X.md

@@ -1,11 +1,11 @@
 <h1 align="center">Обновление из-под NexT v5.1.x</h1>
 
-Между версией 5.1.x и последней версиями нет жёстких изменений. Версия сменилась на мажорную 6 по следующим причинам:
+Между версией 5.1.x и последней версиями нет жёстких изменений. Версия сменилась на мажорную 7 по следующим причинам:
 1. Основной репозиторий перебазировался из профиля [iissnan'а](https://github.com/iissnan/hexo-theme-next) в [theme-next](https://github.com/theme-next) организацию.
 2. Большинство библиотек в `next/source/lib` директории были вынесены в [отдельные репозитории под организацией NexT](https://github.com/theme-next).
-3. 3rd-party плагин [`hexo-wordcount`](https://github.com/willin/hexo-wordcount) был заменён на [`hexo-symbols-count-time`](https://github.com/theme-next/hexo-symbols-count-time) т.к. `hexo-symbols-count-time` не имеет никаких сторонних nodejs зависимостей, не имеет [языкового фильтра](https://github.com/willin/hexo-wordcount/issues/7) что обеспечивает улучшенную производительность при генерации сайта.
+3. 3rd-party плагин [`hexo-wordcount`](https://github.com/willin/hexo-wordcount) был заменён на [`hexo-symbols-count-time`](https://github.com/theme-next/hexo-symbols-count-time) т.к. `hexo-symbols-count-time` не имеет никаких сторонних Node.js зависимостей, не имеет [языкового фильтра](https://github.com/willin/hexo-wordcount/issues/7) что обеспечивает улучшенную производительность при генерации сайта.
 
-Поэтому, я предлагаю обновиться с версии 5 на версию 6 следующим способом:
+Поэтому, я предлагаю обновиться с версии 5 на версию 7 следующим способом:
 
 1. Вы не трогаете старую директорию `next`, а всего-лишь делаете резервные копии файлов NexT:\
    1.1. `config.yml` или `next.yml` (если Вы использовали [дата-файлы](DATA-FILES.md)).\

docs/zh-CN/UPDATE-FROM-5.1.X.md

@@ -1,14 +1,14 @@
 <h1 align="center">从 NexT v5.1.x 更新</h1>
 
-在大多数情况下，NexT V5 版本仍然能够正常运行，但是如果你想获得更多的功能和帮助，还是建议您升级到 NexT V6+ 版本，并移步 [Theme-Next](https://github.com/theme-next/hexo-theme-next) 仓库。
+在使用 Hexo 3 时，NexT V5 版本仍然能够正常运行，但是如果你想获得更多的功能和帮助，还是建议您升级到 NexT V7+ 版本，并移步 [Theme-Next](https://github.com/theme-next/hexo-theme-next) 仓库。
 
-在 5.1.x 版本和新版本之间没有很大的革命性改进。主版本号变更至 6 主要是因为：
+在 5.1.x 版本和新版本之间没有很大的革命性改进。主版本号变更至 7 主要是因为：
 
 1. 主仓库已从 [iissnan 名下](https://github.com/iissnan/hexo-theme-next) 迁移至 [theme-next](https://github.com/theme-next) 组织。
 2. `next/source/lib` 目录下的绝大多数库被移出到了 [NexT 组织的外部仓库](https://github.com/theme-next)中。
-3. 第三方插件 [`hexo-wordcount`](https://github.com/willin/hexo-wordcount) 被 [`hexo-symbols-count-time`](https://github.com/theme-next/hexo-symbols-count-time) 所取代，因为 `hexo-symbols-count-time` 没有任何外部 nodejs 依赖、也没有会导致生成站点时的性能问题 [language filter](https://github.com/willin/hexo-wordcount/issues/7)。
+3. 第三方插件 [`hexo-wordcount`](https://github.com/willin/hexo-wordcount) 被 [`hexo-symbols-count-time`](https://github.com/theme-next/hexo-symbols-count-time) 所取代，因为 `hexo-symbols-count-time` 没有任何外部 Node.js 依赖、也没有会导致生成站点时的性能问题 [language filter](https://github.com/willin/hexo-wordcount/issues/7)。
 
-推荐通过如下步骤从 v5 升级到 v6：
+我们推荐通过如下步骤从 v5 升级到 v7：
 
 1. 并不修改原有的 `next` 目录，而只是复制部分 NexT 文件：
     1. `_config.yml` 或 `next.yml`（如果你使用了[数据文件](DATA-FILES.md)）。
@@ -33,5 +33,7 @@
     从 v6.0.3 版本起，`zh-Hans` 改名为 `zh-CN`：https://github.com/theme-next/hexo-theme-next/releases/tag/v6.0.3
 
     升级到 v6.0.3 及以后版本的用户，需要显式修改 Hexo 主配置文件 `_config.yml` 里的 `language` 配置，否则语言显示不正确。
+5. 更新 Hexo 和 Hexo 插件
+    如果完成了以上步骤后，执行 `hexo s` 或 `hexo g` 出现错误，这意味着可能是旧版的 Hexo 和 Hexo 插件与新版的 NexT 主题产生了冲突。我们建议将 Hexo 升级至 4.0 以上的版本，将 Hexo 插件升级到最新版本。你可以执行 `npm outdated` 查看所有可以升级的插件。
 
 关于第三方库的启用，参见[这里](https://github.com/theme-next/hexo-theme-next/blob/master/docs/zh-CN/INSTALLATION.md#插件)。