fix: Fixes paritytech#13071 change order of ldd command and update ./docker/README.md (paritytech#13072)

* fixes paritytech#13071

* remove warning

Author: ltfschoen

docker/README.md

@@ -1,6 +1,6 @@
 # Substrate Builder Docker Image
 
-The Docker image in this folder is a `builder` image. It is self contained and allow users to build the binaries themselves.
+The Docker image in this folder is a `builder` image. It is self contained and allows users to build the binaries themselves.
 There is no requirement on having Rust or any other toolchain installed but a working Docker environment.
 
 Unlike the `parity/polkadot` image which contains a single binary (`polkadot`!) used by default, the image in this folder builds and contains several binaries and you need to provide the name of the binary to be called.
@@ -12,6 +12,11 @@ You should refer to the .Dockerfile for the actual list. At the time of editing,
 - node-template
 - chain-spec-builder
 
+To generate the latest parity/substrate image. Please first run:
+```sh
+./build.sh
+```
+
 The image can be used by passing the selected binary followed by the appropriate tags for this binary.
 
 Your best guess to get started is to pass the `--help flag`. Here are a few examples:

docker/substrate_builder.Dockerfile

@@ -24,10 +24,10 @@ RUN useradd -m -u 1000 -U -s /bin/sh -d /substrate substrate && \
 	mkdir -p /data /substrate/.local/share/substrate && \
 	chown -R substrate:substrate /data && \
 	ln -s /data /substrate/.local/share/substrate && \
-# unclutter and minimize the attack surface
-	rm -rf /usr/bin /usr/sbin && \
 # Sanity checks
 	ldd /usr/local/bin/substrate && \
+# unclutter and minimize the attack surface
+	rm -rf /usr/bin /usr/sbin && \
 	/usr/local/bin/substrate --version
 
 USER substrate