[misc] add instructions on how to install nvshmem/pplx/deepep (#17964)

Signed-off-by: youkaichao <youkaichao@gmail.com>

tools/ep_kernels/install_system_libraries.sh

@@ -0,0 +1,18 @@
+set -ex
+
+# prepare workspace directory
+WORKSPACE=$1
+if [ -z "$WORKSPACE" ]; then
+    export WORKSPACE=$(pwd)/ep_kernels_workspace
+fi
+
+if [ ! -d "$WORKSPACE" ]; then
+    mkdir -p $WORKSPACE
+fi
+
+# build and install gdrcopy system packages
+pushd $WORKSPACE
+cd gdrcopy_src/packages
+apt install devscripts -y
+CUDA=${CUDA_HOME:-/usr/local/cuda} ./build-deb-packages.sh
+dpkg -i *.deb