Fix wrong documentation

[enjoy-binbin]

This PR also change was extreme long to is extremely long to be precise.

[enjoy-binbin]

btw, i see this:

pexpire | √ | precision is in seconds
pexpireat | √ | precision is in seconds
pttl | √ | precision is in seconds

we says these commands precision is in seconds, is that right? i did not dive into the kvrocks source code
(redis precision is in milliseconds)

[git-hulk]

Hi @enjoy-binbin, thanks for your contribution first.

we says these commands precision is in seconds, is that right? i did not dive into the kvrocks source code

Yes, that's right. Currently, Kvrocks stores the expiration time in 32-bit, so it cannot support the millisecond now. Support those commands are for compatible with Redis, and @PragmaTwice is working on supporting 64-bit expiration time in this PR: apache/kvrocks#1342.

[enjoy-binbin]

@git-hulk great, glad to hear that, thanks for the tip / infomation

[torwig]

LGTM