refactor build dependencies and update docs

Dockerfile

@@ -5,17 +5,13 @@ WORKDIR /dhx/node
 
 COPY . .
 
-RUN apt-get update && apt-get install -y build-essential wget cmake pkg-config libssl-dev \
+# https://substrate.dev/docs/en/knowledgebase/getting-started
+RUN apt-get update && apt-get install -y build-essential wget cmake pkg-config libssl-dev llvm \
     openssl git gcc clang libclang-dev curl vim unzip screen bash \
     && curl https://getsubstrate.io -sSf | bash -s -- --fast \
-    && wget -O - https://sh.rustup.rs | sh -s -- -y \
+    && . /root/.cargo/env \
     && PATH=$PATH:/root/.cargo/bin \
-    && rustup update stable \
-    && rustup update nightly \
-    && rustup toolchain install nightly-2021-03-10 \
-    && rustup target add wasm32-unknown-unknown --toolchain nightly-2021-03-10 \
-    && rustup default nightly-2021-03-10 \
-    && rustup override set nightly-2021-03-10 \
+    && ./scripts/init.sh && \
     && cargo version \
     && rustc --version \
     && cargo build --release

EXAMPLES.md

@@ -10,28 +10,21 @@
 
 ## Install and update: Rust, Substrate, Wasm, and Subkey <a id="chapter-ca1234"></a>
 
-* Install and update dependencies (i.e. cmake, gcc, ssl, llvm, etc)
-    * Refer to the [Dockerfile](./Dockerfile) for details on linux.
-    * Refer to https://getsubstrate.io/ for installation steps on various operating systems.
+* Install and update Build Dependencies by following Substrate Developer Hub instructions https://substrate.dev/docs/en/knowledgebase/getting-started/#1-build-dependencies for your specific operating system
 
-* Install and update Rust, Substrate, Wasm, and Subkey:
+* Install and update Rust, Substrate, Wasm:
 
 ```bash
-curl https://getsubstrate.io -sSf | bash -s -- --fast && \
-cargo install --force subkey --git https://github.com/paritytech/substrate --version 2.0.0 --locked && \
-./scripts/init.sh && \
-. ~/.cargo/env && \
 wget -O - https://sh.rustup.rs | sh -s -- -y && \
+. ~/.cargo/env && \
 PATH=$PATH:~/.cargo/bin && \
-rustup update stable nightly && \
-rustup toolchain install nightly-2021-03-10 && \
-rustup target add wasm32-unknown-unknown --toolchain nightly-2021-03-10 && \
-rustup default nightly-2021-03-10 && \
-rustup override set nightly-2021-03-10 && \
+./scripts/init.sh && \
 cargo version && \
 rustc --version
 ```
 
+* Optionally install Subkey from https://substrate.dev/docs/en/knowledgebase/integrate/subkey
+
 ## Example "dev" development PoS testnet (with single node) <a id="chapter-f21efd"></a>
 
 ### Intro

scripts/init.sh

@@ -4,6 +4,7 @@ set -e
 
 echo "*** Initializing WASM build environment"
 
+rustup default stable
 rustup update stable
 rustup update nightly
 rustup toolchain install nightly-2021-03-10