Copy updates for IO & Sorting Chapter (quii#386)

* Update outdated descriptions and links (quii#358)

* Update reflection.md (quii#361)

Code examples for chan and func are incorrect

* Update select.md (quii#371)

Hi all,

I've been following this repo to help teach myself go and it's been a great help.
I noticed on line 399 the first argument in t.Run doesn't match the assertion. Raising this PR for your consideration as to whether you think this wording fits better or not.

* first quarter of edits

* 2nd quarter of chapter copy updates

* third quart of chapter's copy changes

* copy change to instructions and example (combining instructions to create a single code example)

* adding code example

* finishing up edits for io

* copy changes for cli

* Revert "copy changes for cli"

This reverts commit 1d9aff2.

Co-authored-by: 森 優太 mori <59682979+uta-mori@users.noreply.github.com>
Co-authored-by: Johan Baaij <johanbaaij@gmail.com>
Co-authored-by: Brady <37232811+BClark88@users.noreply.github.com>