remove references to io.js from doc

[gireeshpunathil]

Is your feature request related to a problem? Please describe.

merger happened long back, and predates the earliest supported versions.

Describe the solution you'd like
remove references to io.js from the docs, aiming to reduce confusion.

Describe alternatives you've considered
status-quo.

[aduh95]

I was able to find one occurence in Process page:

node/doc/api/process.md

Lines 1764 to 1765 in 83eaaf9

	* `name` {string} A value that will always be `'node'` for Node.js. For
	legacy io.js releases, this will be `'io.js'`.

Is there more?

[antsmartian]

@aduh95 Yes even I ran a regex found only such instance. I believe this is a good first issue. Tagging it.

[hexxdump]

Can I take this and work on fixing the docs ?

[lpinca]

Closing as this has been fixed by #35618.