Add frontmatter warning for mapped_pages edits

[Copilot]

Most contributors should not add or modify mapped_pages in doc frontmatter; that metadata should be maintained by technical writers. This PR introduces a dedicated Vale warning to flag those edits while keeping guidance explicit in lint output.

• New lint rule: Elastic.MappedPages

  • Adds styles/Elastic/MappedPages.yml.
  • Triggers a warning when mapped_pages appears inside YAML frontmatter (supports LF/CRLF).
  • Uses reviewer-updated wording that emphasizes rare scenarios and asks contributors to consult their local technical writer before pushing changes.

• Rule coverage in existing lint fixture flow

  • Updates .github/test-fixtures/sample-violations.md to include frontmatter with mapped_pages.
  • Updates .github/workflows/test-lint.yml to assert Elastic.MappedPages fires in the fixture-based rule check list.

• Repo hygiene adjustment

  • Updates .gitignore to ignore Python bytecode/cache artifacts and removes previously tracked cache files from lint/ and report/.

# styles/Elastic/MappedPages.yml
extends: existence
message: "mapped_pages should only be added or updated in rare scenarios. Talk with your local technical writer before pushing changes to this key."
level: warning
nonword: true
scope: raw
tokens:
  - '(?ms)\A---\r?\n.*?^[ \t]*mapped_pages:.*?^---'

[bmorelli25]

LG from my perspective. Ready for a review from someone else

[github-actions]

Vale Linting Results

Summary: 11 warnings, 9 suggestions found

⚠️ Warnings (11)

File	Line	Rule	Message
.github/test-fixtures/sample-violations.md	2	Elastic.MappedPages	mapped_pages should only be added or updated in rare scenarios. Talk with your local technical writer before pushing changes to this key.
.github/test-fixtures/sample-violations.md	6	Elastic.Articles	Use 'an FAQ' instead of 'a FAQ'. The article depends on pronunciation, not spelling.
.github/test-fixtures/sample-violations.md	6	Elastic.Articles	Use 'an HTML' instead of 'a HTML'. The article depends on pronunciation, not spelling.
.github/test-fixtures/sample-violations.md	6	Elastic.Articles	Use 'an SQL' instead of 'a SQL'. The article depends on pronunciation, not spelling.
.github/test-fixtures/sample-violations.md	6	Elastic.Articles	Use 'an HTML' instead of 'a HTML'. The article depends on pronunciation, not spelling.
.github/test-fixtures/sample-violations.md	7	Elastic.BritishSpellings	Use American English spelling 'optimize' instead of British English 'optimise'.
.github/test-fixtures/sample-violations.md	7	Elastic.BritishSpellings	Use American English spelling 'customize' instead of British English 'customise'.
.github/test-fixtures/sample-violations.md	7	Elastic.BritishSpellings	Use American English spelling 'behavior' instead of British English 'behaviour'.
.github/test-fixtures/sample-violations.md	11	Elastic.DontUse	Don't use 'just'.
.github/test-fixtures/sample-violations.md	11	Elastic.DontUse	Don't use 'please'.
.github/test-fixtures/sample-violations.md	11	Elastic.DontUse	Don't use 'aka'.

💡 Suggestions (9)

File	Line	Rule	Message
.github/test-fixtures/sample-violations.md	8	Elastic.WordChoice	Consider using 'efficiently' instead of 'Simply', unless the term is in the UI.
.github/test-fixtures/sample-violations.md	8	Elastic.WordChoice	Consider using 'allowlist' instead of 'whitelist', unless the term is in the UI.
.github/test-fixtures/sample-violations.md	8	Elastic.WordChoice	Consider using 'blocklist' instead of 'blacklist', unless the term is in the UI.
.github/test-fixtures/sample-violations.md	9	Elastic.OxfordComma	Use the Oxford comma in 'reading, writing and executing.'.
.github/test-fixtures/sample-violations.md	10	Elastic.Wordiness	Consider using 'to' instead of 'In order to'.
.github/test-fixtures/sample-violations.md	10	Elastic.Wordiness	Consider using 'because' instead of 'due to the fact that'.
.github/test-fixtures/sample-violations.md	10	Elastic.Wordiness	Consider using 'many' instead of 'a large number of'.
.github/test-fixtures/sample-violations.md	12	Elastic.Exclamation	Use exclamation points sparingly. Consider removing the exclamation point.
.github/test-fixtures/sample-violations.md	12	Elastic.Exclamation	Use exclamation points sparingly. Consider removing the exclamation point.

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To use Vale locally or report issues, refer to Elastic style guide for Vale.