Doc: Update Linux build docs for Rocky and RHEL

[TomShawn]

This PR updates the steps of building CBDB on Rocky and RHEL systems. In addition, this PR briefly adds links to README file.

Will be merged after #272.

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[TomShawn]

@tuhaihe @Zhangbaowen-Hashdata @Ray-Eldath PTAL, thanks~ The content source is provided by @Zhangbaowen-Hashdata.

[tuhaihe]

Approved. Verified successfully on my machine.