fix(glyphs): winDescent metric to be positive

Per the spec, it should be positive instead of a negative number like
the others.

Author: caidanw

fonts/ServerMono.glyphs

@@ -17,8 +17,7 @@ nhH0o_",
 "200%",
 "/.notdef",
 "/.notdef ▂▃▄▅▆▇█▀▔▏▎▍▌▋▊▉▐▕▖▗▘▙▚▛▜▝▞▟░▒▓●○◦◊■□▲▶▼◀▴▾◂╦╗╔═╩╝╚║╬╣╠╥╖╓┰┒┧┎┟╁┯┑┩┍┡╇╤╕╒╍╏╻┳┓┏━╸╾┉┋╺┅┇╹┻┛╿┗┃╋┫┣╅┭┵┽┲┺╊╃╮╭╯╰╌╎╳╲╱╷┬┐┌─╴╼┈┊╶┄┆╵╽┴┘└│┼┤├╆┮┶┾┱┹╉╄╨╜╙╀┸┦┚┞┖╈┷┪┙┢┕╧╛╘╫╢╟╂┨┠┿┥┝╪╡╞",
-"▁▂▃▄▅▆▇█▀▏▎▍▌▋▊▉▐",
-"◂"
+"▁▂▃▄▅▆▇█▀▏▎▍▌▋▊▉▐"
 );
 axes = (
 {
@@ -402,7 +401,7 @@ value = 900;
 },
 {
 name = winDescent;
-value = -200;
+value = 200;
 }
 );
 guides = (