[Doc-SIG] using the same delimiter on the left and right..

[Goodger, David]

Guido van Rossum writes:
> In many fonts, backtick is hard to distinguish from apostrophe!

In many fonts, '1' (one) is hard to distinguish from 'l' (el), or 'O'
(upcase oh) from '0' (zero). Programmers (& other docstring writers) ought
to choose a programmer-friendly font. ;->

/DG