chore: add screenshot for gpm
chore: add screenshot for gpm

bdronneau/grav-theme-bootflat,basti1dr/grav-theme-bootflat,basti1dr/grav-theme-bootflat,bdronneau/grav-theme-bootflat,bdronneau/grav-theme-bootflat,basti1dr/grav-theme-bootflat