message: docs: update get-ckb.md
diff: ## Download from Releases
  -We will publish binaries for each release via [Github Releases](https://github.com/nervosnetwork/ckb/releases). If your system
  +We will publish binaries for each release via [Github Releases]. If your system
  is listed there, you can download the package directory.
  +[Github Releases]: https://github.com/nervosnetwork/ckb/releases
  +
  There is also a repository [ckb-builds](https://github.com/ckb-builds/ckb-builds/releases) containing the nightly builds from the develop
  branch.
  CentOS users please use the `x86_64-unknown-centos-gnu` package. Both Linux
  and CentOS builds require OpenSSL 1.0 to run.
  -- Ubuntu: `sudo apt-get install libssl1.0.0`
  +- Ubuntu and Debian: `sudo apt-get install libssl1.0.0`
  +- Arch Linux: `sudo pacman -Sy openssl-1.0`
  - CentOS: `sudo yum install openssl-libs`
  We also provides docker images, see [how to run CKB with docker](run-ckb-with-docker.md).
  @@ -74,32 +77,38 @@ export SNAPPY_LIB_DIR=/usr/local/lib
  ### Build from source
  -The `master` branch is regularly built and tested. It is always the latest released version. The default checked out branch `develop` is the latest version in development.
  +The `master` branch is regularly built and tested. It is always the latest
  +released version. The default checked out branch `develop` is the latest
  +version in active development.
  It is recommended to build a version from master.
  +You can download the source code of [master
  +branch](https://github.com/nervosnetwork/ckb/archive/master.zip) from GitHub,
  +or a history version from [GitHub Releases].
  +
  +You also can choose to clone the code via git:
  +
  ```bash
  # get ckb source code
  git clone https://github.com/nervosnetwork/ckb.git
  cd ckb
  git checkout master
  -
  -# build in release mode
  -make build
  ```
  -This will build the executable `target/release/ckb`. Please add the directory
  -to `PATH` or copy/link the file into a directory already in the `PATH`.
  +It is easy to switch to a history version and build, for example, check out
  +v0.12.2.
  ```bash
  -export PATH="$(pwd)/target/release:$PATH"
  -# or
  -# ln -snf "$(pwd)/target/release/ckb" /usr/local/bin/ckb
  +git checkout -b branch-v0.12.2 v0.12.2
  ```
  -It is easy to switch to a history version and build, for example, check out
  -v0.8.0:
  +Run `make prod` inside the source code directory. It will build the executable
  +`target/release/ckb`. Please add the directory to `PATH` or copy/link the file
  +into a directory already in the `PATH`.
  ```bash
  -git checkout -b branch-v0.8.0 v0.8.0
  +export PATH="$(pwd)/target/release:$PATH"
  +# or
  +# ln -snf "$(pwd)/target/release/ckb" /usr/local/bin/ckb
  ```
  