Update INSTALL.md

INSTALL.md

@@ -158,6 +158,8 @@ If everything works, then the following ROM should be built:
 
 A Dockerfile is provided for your convenience. To begin, setup docker on your local machine following the instructions at https://docs.docker.com/desktop/. Then, run
 
-    ./clean.sh
+    ./clean.sh  # because we are switching environments
     docker build . -t pret/pokeplatinum
-    docker run -w /rom -v .:/rom pret/pokeplatinum sh -c "./config.sh && ./build.sh"
+    docker run -u $USER -w /rom -v .:/rom pret/pokeplatinum ./config.sh  # first time only
+    docker run -u $USER -w /rom -v .:/rom pret/pokeplatinum ./build.sh
+    docker run -u $USER -w /rom -v .:/rom pret/pokeplatinum ./clean.sh  # before switching environments