[WIP] Word tuning, command example adjustments

This "alias" wording was inconsistent with line [205](https://github.com/github/training-kit/pull/154/files#diff-b4d2d7ea78194053ba9cb92faf3bfba6R205) and [210](https://github.com/github/training-kit/pull/154/files#diff-b4d2d7ea78194053ba9cb92faf3bfba6R210).

It's probably best if we stay consistent with Git terminology and refer to the URL/repository location as the `remote` across all examples.