Improve the experience to build and run ckb

[doitian]

https://talk.nervos.org/t/experience-report-first-time-building-and-running-ckb/4518

• Just let users to build using cargo build or cargo build --release. The crate faketime is designed that it has little overhead when it is not used, so don't bother developers with it.
• Add a VERSIONS file to trace of the the corresponding ckb-cli, ckb-bench versions.
• Print genesis and spec hash in ckb init
• ckb-cli should prints a warning in debug build that some commands are extremely slow.
• Improve the comment for block assembler
  • Simplify the comment to explain how to setup a simple secp256k1 lock in testnet/mainnet.
  • Use a public-known key pair in dev chain.
  • Write an essay to explain the advantage usage of block assembler.

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#2256 (comment)

• Apple M1 support

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[zhangsoledad]

• Apple M1 support