Use 'builddir' instead of 'build' in the README
Use 'builddir' instead of 'build' in the README

Clarifies that this is really just a directory, not a command.

https://github.com/mesonbuild/meson/issues/1560

becm/meson,becm/meson,ernestask/meson,ernestask/meson,ernestask/meson,QuLogic/meson,trhd/meson,jpakkane/meson,wberrier/meson,mesonbuild/meson,QuLogic/meson,trhd/meson,mesonbuild/meson,jeandet/meson,aaronp24/meson,mesonbuild/meson,wberrier/meson,MathieuDuponchelle/meson,rhd/meson,fmuellner/meson,pexip/meson,aaronp24/meson,wberrier/meson,MathieuDuponchelle/meson,becm/meson,fmuellner/meson,rhd/meson,fmuellner/meson,thiblahute/meson,aaronp24/meson,aaronp24/meson,jpakkane/meson,jeandet/meson,aaronp24/meson,pexip/meson,thiblahute/meson,mesonbuild/meson,jeandet/meson,QuLogic/meson,jpakkane/meson,trhd/meson,jpakkane/meson,thiblahute/meson,trhd/meson,ernestask/meson,becm/meson,rhd/meson,thiblahute/meson,rhd/meson,fmuellner/meson,mesonbuild/meson,mesonbuild/meson,QuLogic/meson,fmuellner/meson,fmuellner/meson,thiblahute/meson,MathieuDuponchelle/meson,ernestask/meson,thiblahute/meson,rhd/meson,ernestask/meson,pexip/meson,jeandet/meson,QuLogic/meson,pexip/meson,rhd/meson,becm/meson,trhd/meson,MathieuDuponchelle/meson,pexip/meson,trhd/meson,wberrier/meson,becm/meson,QuLogic/meson,rhd/meson,jpakkane/meson,pexip/meson,jeandet/meson,aaronp24/meson,jpakkane/meson,ernestask/meson,QuLogic/meson,ernestask/meson,becm/meson,wberrier/meson,jpakkane/meson,aaronp24/meson,QuLogic/meson,wberrier/meson,MathieuDuponchelle/meson,trhd/meson,jpakkane/meson,mesonbuild/meson,becm/meson,fmuellner/meson,QuLogic/meson,wberrier/meson,jeandet/meson,trhd/meson,wberrier/meson,becm/meson,ernestask/meson,jpakkane/meson,fmuellner/meson,thiblahute/meson,fmuellner/meson,trhd/meson,jeandet/meson,MathieuDuponchelle/meson,jeandet/meson,mesonbuild/meson,becm/meson,pexip/meson,thiblahute/meson,mesonbuild/meson,MathieuDuponchelle/meson,pexip/meson,jeandet/meson,pexip/meson,rhd/meson,pexip/meson,mesonbuild/meson,MathieuDuponchelle/meson,aaronp24/meson,aaronp24/meson,thiblahute/meson,MathieuDuponchelle/meson