添加底栏按钮，支持通过底栏按钮触发字符串转换；更新 README.md；release version 1.0.6

package.json

@@ -2,7 +2,7 @@
   "name": "variable-conversion",
   "displayName": "Variable Conversion",
   "description": "一个强大的变量名转换插件，支持右键菜单、快捷键、底栏等多种方式使用，支持小驼峰、大驼峰(帕斯卡)、下划线(蛇形)、连字符(脊柱式)、全小写、全大写等常用命名方式(及组合)转换。 \nA powerful variable naming conversion extension. You can use it through the editer menu, shortcut keys and bottom bar. Support camel, pascal, snake, kebab(spinal), lower, upper case, and more.",
-  "version": "0.0.5",
+  "version": "0.0.6",
   "icon": "image/logo.png",
   "publisher": "coder-xiaomo",
   "engines": {