Fix 8 broken links (#4837) (#4842)
Fix 8 broken links (#4837) (#4842)

* cherry pick #4837 to master

Signed-off-by: ti-srebot <9a5274fd6b0ebeffb8aa3de76839934d21be0c45@pingcap.com>

* conflicts

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>
pingcap/docs-cn,pingcap/docs-cn