bug#32210: Support medium weighted fonts

[Robert Pluim]

>>>>> On Mon, 18 Nov 2019 11:28:49 +0100, Lars Ingebrigtsen <larsi@gnus.org> 
>>>>> said:
    Lars> and tried using the gtk selector (via M-x menu-set-font).  I only have
    Lars> one font installed that has both normal and medium variations "Nimbus
    Lars> no9", so I tried that.  And I got:

    Lars> Weight: 400, symbol normal
    Lars> Weight: 700, symbol bold

    Lars> And, yes, the thing that's called Nimbus No9 Medium does look like a
    Lars> bold in both the gtk selector and in Emacs.  So I don't think I have a
    Lars> proper font to experiment with...  does anybody know of a font in 
Debian
    Lars> Stable that has both varieties?  SauceCodePro was the example in the
    Lars> bug report, but that does not seem to be available here.

I tried here with 'Noto Sans CJK HK', which seems to have every
variant under the sun, and got:

Weight: 400, symbol normal
Weight: 500, symbol semi-bold

I donʼt know if Debian Stable has that font.

Robert