docs: pangofc-fontmap: Fix typo in "Since" tag
docs: pangofc-fontmap: Fix typo in "Since" tag

danny-ku/pango,Distrotech/pango,Distrotech/pango,danny-ku/pango,kari-lentz/alpha-pango,kari-lentz/alpha-pango,kari-lentz/alpha-pango,danny-ku/pango,kari-lentz/alpha-pango,Distrotech/pango