[docs] Improve -O docs (issue 17232)

[tjreedy at udel.edu]

https://bugs.python.org/review/17232/diff/7583/Doc/using/cmdline.rst
File Doc/using/cmdline.rst (right):

https://bugs.python.org/review/17232/diff/7583/Doc/using/cmdline.rst#newcode214
Doc/using/cmdline.rst:214: :const:`__debug__`.  Change the filename
extension for compiled
On 2013/03/14 08:47:00, ezio.melotti wrote:
> Does this link to the place where __debug__ is documented (assuming
there is
> such place)?

https://docs.python.org/3/library/constants.html#__debug__

https://bugs.python.org/review/17232/diff/7583/Doc/using/cmdline.rst#newcode221
Doc/using/cmdline.rst:221: Discard docstrings in addition to what
:option:`-O` does.
On 2013/03/14 08:47:00, ezio.melotti wrote:
> What about "Like :option:`-O`, but also discard docstrins."?

At the time I wrote this, -00 *is* -0 + discard docstrings.   I see the
point of mentioning things in this order.  Perhaps

Do :option:`-O` and also discard docstrings.

https://bugs.python.org/review/17232/diff/7583/Modules/main.c
File Modules/main.c (right):

https://bugs.python.org/review/17232/diff/7583/Modules/main.c#newcode69
Modules/main.c:69: -O     : remove assert and __debug__-dependent
statements; change .py\n\
On 2013/03/14 08:47:00, ezio.melotti wrote:
> Shouldn't this be .pyc?

Yes

https://bugs.python.org/review/17232/diff/7583/Modules/main.c#newcode71
Modules/main.c:71: -OO    : remove doc-strings in addition to the -O
changes\n\
On 2013/03/14 08:47:00, ezio.melotti wrote:
> I would re-use the same wording I proposed for the docs.

I suggested a slightly different replacement.

-OO     : do -O and also discard docstrings\n\

https://bugs.python.org/review/17232/