RFR: Amend Requesting a change

[Alexey Ivanov]

A follow-up to #155 where I submitted suggestions after the issue was integrated. I applied [my suggestions](https://github.com/openjdk/guide/pull/155#discussion_r2257971819) in this PR.

* Fix a few typos;
* Clarify the sentences.

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Commit messages:
 - Amend Requesting a change

Changes: https://git.openjdk.org/guide/pull/157/files
  Webrev: https://webrevs.openjdk.org/?repo=guide&pr=157&range=00
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/guide/pull/157.diff
  Fetch: git fetch https://git.openjdk.org/guide.git pull/157/head:pull/157

PR: https://git.openjdk.org/guide/pull/157