Rename --version to --electron-version

[malept]

There seem to be a disproportionate number of issues created over the confusion around what --version actually means. (See: #137, #140, #153.) I propose that the parameter be renamed so that it's obvious as to what the flag's value refers to: the version of Electron, not the version of the application.

This would obviously be a breaking change, requiring a major version bump.

[max-mapper]

I'd rather try and fix this with docs first. The readme formatting could use some love, e.g. the usage section is currently a big wall of unicode text

[malept]

I figured as much. I just wanted to get this idea out there and documented.

I'll take a crack at making the README friendlier tonight, if I have some time.

Closing for now.

[malept]

I'm reopening this. No amount of docs has fixed this so far. In my opinion, this option violates the principle of least astonishment.

Here's the specification for how this should work:

1. Write a pull request to add electronVersion to the API, and --electron-version to the CLI arguments. Deprecate the --version argument. Make it really clear in the docs and when it's used (instead of electronVersion) that the --version argument is deprecated.
2. Maintainer releases a minor version with this change.
3. Write a pull request to remove --version and associated deprecation warnings.
4. Maintainer releases a major version with this change.