Add plugin version in config.json

[crguezl]

@GGCristo

This issue is related with issue #3

I see that the list of installed plugins is in the command section of the config.json file. It does not include the plugin version.

  "commands": {
    "view": {
      "originalName": "gh-cli-for-education/gh-edu-view"
    }

may be we must keep also the version of the installed plugins