[zh_CN] done /zh/controllers/request-response.rst
[zh_CN] fix error: ``AppHelper` -> ``AppHelper``
Merge pull request #1839 from blackpuppy/zh

[zh_CN] done /zh/controllers/request-response.rst
Minor spelling/grammar corrections

Corrected grammar errors in Spanish.

Source: native language.
Merge pull request #1840 from MightyBranch/patch-1

Minor spelling/grammar corrections
[zh_CN] done /zh/controllers/pages-controller.rst
Merge branch 'master' into zh-work