bugfix:modify the words spelling mistakes

[Aresforchina]

Ⅰ. Describe what this PR did

Increase the quality of articles and correct spelling mistakes

Ⅱ. Does this pull request fix one issue?

NONE

Ⅲ. Why don't you add test cases (unit test/integration test)? (你真的觉得不需要加测试吗？)

do not need

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[pouchrobot]

Thanks for your contribution. 🍻 @Aresforchina
While we thought PR TITLE could be more specific, longer than 20 chars.
Please edit this PR title instead of opening a new one.
More details, please refer to https://github.com/dragonflyoss/Dragonfly/blob/master/CONTRIBUTING.md

[pouchrobot]

We found this is your first time to contribute to Dragonfly, @Aresforchina
👏 We really appreciate it.
Just remind that you have read the contribution guide: https://github.com/dragonflyoss/Dragonfly/blob/master/CONTRIBUTING.md
If you didn't, you should do that first. If done, welcome again and please enjoy hacking! 🍻

[codecov-io]

Codecov Report

Merging #1133 into master will not change coverage.
The diff coverage is 0%.

@@           Coverage Diff           @@
##           master    #1133   +/-   ##
=======================================
  Coverage   47.22%   47.22%           
=======================================
  Files         116      116           
  Lines        7204     7204           
=======================================
  Hits         3402     3402           
  Misses       3535     3535           
  Partials      267      267

Impacted Files	Coverage Δ
pkg/errortypes/supernode_errors.go	0% <ø> (ø)	⬆️
supernode/daemon/mgr/cdn/super_reader.go	22.61% <0%> (ø)	⬆️

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[allencloud]

I found lots of such issue in this repo: https://github.com/dragonflyoss/Dragonfly/search?q=unknow&unscoped_q=unknow
Could you help to fix them all? @Aresforchina Thanks

[Aresforchina]

@allencloud Of course, I'll fix them

[yunfeiyanggzq]

@allencloud Of course, I'll fix them

any progress? if you want to fix them in other prs,I can merge this pr

[starnop]

LGTM.

any progress? if you want to fix them in other prs,I can merge this pr

@yunfeiyanggzq I don't think it's a good idea. We should fix the same problem in one PR as much as possible. 😄