Enhance documentation

[yuriy-fix]

Enhance documentation with missing information.
The following is missing for the release process:

1. need to provide a GitHub token.
2. need to provide npm credentials
3. need to provide Bender credentials.

[web-padawan]

We can add a hint on how to create a config file manually. It should be located at ~/.config/configstore/magi-cli.json

Here is how the content should look like:

{
  "github": {
    "com": {
      "username": "USER",
      "token": "TOKEN"
    }
  },
  "bender": {
    "vaadin": {
      "com": {
        "username": "USER",
        "password": "PASSWORD"
      }
    }
  }
}