Tighten Streams docs style across observability pages

[Copilot]

This update resolves the Vale style sweep findings in the Streams docs subtree, covering wording, phrasing, and one punctuation issue across 5 pages.

• Wording cleanup

  • Replaced flagged phrases such as “some of the” → “some”, “In most cases” → “Usually”, and “may” → “might”.
  • Swapped “disable” for “turn off” in the wired streams setup instructions.

• Grammar and punctuation

  • Moved the quoted punctuation in the flagged Streams wording.
  • Kept the affected wording aligned with the Elastic style guide without changing meaning.

• Docs wording simplification

  • Simplified the concat processor parameter description.
  • Removed the redundant “of” in the schema inheritance sentence.

Example:

Wired streams are on by default. To turn off wired streams: