🚀 Feature: Soft-deprecate noHighlighting

[boneskull]

noHighlighting is a browser-only option can supply which disables syntax highlighting.

It should probably be replaced with a reporter option (though open to debate!), since it's unique to the html reporter. This should be a boolean option which defaults to true.

If a user supplies {noHighlighting: true} to mocha.setup() or calls mocha.noHighlighting() in the browser, we should print a deprecation message along the lines of "noHighlighting is deprecated; provide {reporterOption: {highlight: false}} to mocha.setup().

This is what needs to be done:

• The former case can be caught in the browser setup method; see deprecation notices in the Mocha constructor for examples.
• The latter case can be addressed by calling utils.deprecate(...) within Mocha#noHighlighting.
• The html reporter's constructor should accept a reporterOptions object, which may be undefined, and may have a boolean highlight property. If the property is anything other than explicitly false, default to true
• The reporter's constructor should execute Mocha.utils.highlightTags('code') when the end event is emitted by the runner property; use the check for document found here and the value of highlight prop passed in reporterOptions.
• Remove those checks from the callback in browser-entry.js.
• Please add unit tests which assert the new behavior in test/unit/mocha.spec.js.
• Update documentation (docs/index.md) about the deprecation and new behavior.

[boneskull]

Fair warning: this is labeled good-first-issue with some hesitation; it's not a nontrivial task.

[Mia-jeong]

Hi :) I just made a PR about it. While I was working on it I found out a bug related to noHighlighting and I referred it to the PR as well. I would like to thank you that I was able to do it because you wrote everything in very detail.