Make the jump-error-plugin usable

[Marduk Bolaños]

The jump-error-plugin works great! Thank you. However, it is missing a repo.json file in order to be recognized my micro. I wrote one if you do not want to start from scratch:

[{
  "Name": "gutter",
  "Description": "Jump between linter errors",
  "Website": "https://github.com/tommyshem/micro-editor-stuff/tree/main/micro-jump-error-plugin",
  "Versions": [
    {
      "Version": "1.0.0",
      "Require": {
        "micro": ">=2.0.0-1"
      }
    }
  ]
}]

Also, the installation instructions reveal that previously this plugin had its own repository, which I think is a good idea. Anyway, please provide accurate installation instructions, so that more people can benefit from your work :)