message: polish README.md, add instructions for archlinux
diff: @@ -29,7 +29,7 @@ The contribution workflow is described in [CONTRIBUTING.md](CONTRIBUTING.md), an
  ## Build dependencies
  -Nervos is currently tested mainly with `stabe-1.29.2`.
  +Nervos is currently tested mainly with `stable-1.29.2`.
  We recommend installing Rust through [rustup](https://www.rustup.rs/)
  @@ -57,6 +57,17 @@ sudo ln -s /usr/lib/gcc/x86_64-linux-gnu/7/include/stdarg.h /usr/include/stdarg.
  sudo ln -s /usr/lib/gcc/x86_64-linux-gnu/7/include/stddef.h /usr/include/stddef.h
  ```
  +* Archlinux
  +
  +```shell
  +sudo pacman -Sy git autoconf flex bison texinfo libtool pkg-config openssl-1.0 clang
  +```
  +
  +If you get openssl related errors in compiling, try the following environment variables to specify openssl-1.0:
  +
  +```shell
  +OPENSSL_INCLUDE_DIR=/usr/include/openssl-1.0 OPENSSL_LIB_DIR=/usr/lib/openssl-1.0 cargo build --release
  +```
  * OSX:
  @@ -69,10 +80,14 @@ brew install autoconf libtool
  ## Build from source & testing
  ```bash
  -# download Nervos
  +# get ckb source code
  git clone https://github.com/nervosnetwork/ckb.git
  cd ckb
  +# get ckb-vm submodule
  +git submodule init
  +git submodule update
  +
  # build in release mode
  cargo build --release
  ```
  