Undocumented `readline` methods

[sindresorhus]

There are several exposed methods on readline that are not documented:

• readline.getStringWidth()
• readline.isFullWidthCodePoint()
• readline.stripVTControlCharacters()
• readline.emitKeypressEvents()

They should IMHO either be documented or made internal. Preferably the latter.

Most of these are already modules on npm anyways:

• getStringWidth → string-width
• isFullWidthCodePoint → is-fullwidth-code-point
• stripVTControlCharacters → strip-ansi

[tejasmanohar]

@sindresorhus Just submitted a PR for these.

[Fishrock123]

PR: #3847

[cjihrig]

I'm going to keep this open, as #3862 doesn't cover readline.emitKeypressEvents(). On the last CTC call, the discussion to deprecate or document this function was tabled.

[jasnell]

@cjihrig ... do we still need to keep this one open?