font_shaper
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font_shaper#
specifies the method by which text is mapped to glyphs in the available fonts.
The shaper is responsible for handling kerning, ligatures and emoji
composition. The default is Harfbuzz and we have very preliminary support
for Allsorts.
It is strongly recommended that you use the default Harfbuzz shaper.
The incomplete Allsorts shaper was removed.