Add no color option

[adamdmharvey]

Fixes #36. This is an attempt to add the command line parameter to support no color mode.

• Added -z / --no-color.
• Re-aligned the command line options code to make it easier to edit.
• Disabled color via _chalk, and added square brackets around spelling mistakes, such as: [[[mistaeks]]].
• Updated README.md

Two outstanding questions for feedback:

1. Couldn't decide on the best single letter for the parameter, so I went with -z. -c seemed more like it would ENABLE color, not disable it. Happy for feedback to adjust it. Could possibly simply use --no-color and no single letter if preferred?
2. I thought the triple square brackets worked, but open to other's opinions?

I couldn't find any CONTRIBUTING guidelines, so I am simply submitting straight into master. Hope that's ok!

[adamdmharvey]

Changed the parameter to --no-colour and updated the docs/code as appropriate, so it would pass the pipeline spell check. :)

[adamdmharvey]

I also notice on the README you said the next major version may switch to US English? If so, I can a) put color back, and b) update the pipeline to force english spell checking, which should allow it to pass the CI.

[RyanCopley]

@lukeapage Could this please be merged? It would be very helpful

[dduportal]

Hello and thanks for all of this work!

As an end user, I'm giving a 👍 to this feature. Not only this spellchecker is NEAT, but also this feature !

[magnoliaceiling]

This merge would be so incredibly helpful, I don't suppose it could be merged in @robatwilliams or @lukeapage?