Updated Compile in MacOS (markdown)

Compile-in-MacOS.md

@@ -53,6 +53,7 @@ In a terminal, run:
     cd /opt/build
     curl -Ok https://pkg-config.freedesktop.org/releases/pkg-config-0.29.2.tar.gz
     tar xf pkg-config-0.29.2.tar.gz 
+    cd pkg-config-0.29.2
     mkdir build
     cd build
     ../configure --prefix=/opt/install/pkg-config-0.29.2 --with-internal-glib