[Bug Report] dependencies weren't been uninstalled while uninstalling HackMD

[yc5]

1. Before I install HackMD

   

2. After installed HackMD

   

3. Uninstalled HackMD and reload window

   

[Yukaii]

Umm, it seems to be the behavior of VSCode. HackMD VSCode extension depends on these extensions:

	"extensionDependencies": [
		"bierner.markdown-preview-github-styles",
		"bierner.markdown-emoji",
		"bierner.emojisense",
		"bierner.markdown-image-size",
		"bierner.markdown-footnotes",
		"bierner.markdown-checkbox"
	],