Implement missing commands (version, migrate and render) #6
Description
There are 3 commands that aren't implemented but are available from the Hexo CLI. hexo version, render and migrate. I tried to implement version myself but unfortunately I don't understand TypeScript or VSCode child process or terminal API handling well enough. Even when referencing how its done in the vscode-hugo extension I was unable to come up with a working version.
However, feel free to use what I have so far or if you want I can create a pull request for you to finish off work on the version part at least.