stack ghci: Make shown options easily copy-pastable.

[nh2]

Turns

	1. Package `p' component exe:myexe with main-is file ...

into

	1. Package `p' component p:exe:myexe with main-is file ...

so that you can easily copy-paste it into

stack ghci p:exe:myexe

Note: Documentation fixes for https://docs.haskellstack.org/en/stable/ should target the "stable" branch, not master.

Please include the following checklist in your PR:

• Any changes that could be relevant to users have been recorded in the ChangeLog.md
• The documentation has been updated, if necessary (not necessary).

---

• I haven't tested the change yet, as it's still compiling. Now tested.

[mihaimaruseac]

Thank you