Update showdowns deps to version 0.5.7.

Author: jhuix

package.json

@@ -23,12 +23,12 @@
     "README.md"
   ],
   "dependencies": {
-    "@jhuix/showdowns": "^0.5.5",
+    "@jhuix/showdowns": "^0.5.7",
     "vue-codemirror": "^4.0.6"
   },
   "devDependencies": {
     "@vue/cli-plugin-babel": "^4.5.7",
-    "@vue/cli-plugin-eslint": "^4.5.7",
+    "@vue/cli-plugin-eslint": "^5.0.8",
     "@vue/cli-plugin-vuex": "^4.5.7",
     "@vue/cli-service": "^4.5.7",
     "@vue/eslint-config-prettier": "^6.0.0",

vue.config.js

@@ -63,7 +63,7 @@ module.exports = {
       // 在 dist/index.html 的输出
       filename: 'index.html',
       // 当使用 title 选项时，template 中的 title 标签需要是 <title><%= htmlWebpackPlugin.options.title %></title>
-      title: 'markdown-showdowns-editor',
+      title: 'vue-showdowns-editor',
       // 在这个页面中包含的块，默认情况下会包含
       // 提取出来的通用 chunk 和 vendor chunk。
       chunks: ['chunk-vendors', 'chunk-common', 'index']