[POC] Turn org and repo arguments into options

                       
| Q             | A   |
| ---           | --- |
| Bug fix?      | n   |
| New feature?  | y   |
| BC breaks?    | n   |
| Deprecations? | n   |
| Tests pass?   | y   |
| Fixed tickets | #76  |
| License       | MIT |
| Doc PR        |     |

Should we make the ubiquitous `org` and `repo` arguments options?

They are actually optional and if we keep them as arguments that blocks situations where you want to pass an argument, e.g. `issue:show 1234`