feat: document formatter.trailingNewline

[ematipico]

Summary

Documentation for biomejs/biome#8334

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[coderabbitai]

Walkthrough

This change documents a new top-level formatter option `formatter.trailingNewline` and adds equivalent per-language options (`javascript.formatter.trailingNewline`, `json.formatter.trailingNewline`, `css.formatter.trailingNewline`, `graphql.formatter.trailingNewline`, `grit.formatter.trailingNewline`, `html.formatter.trailingNewline`) in the configuration reference. Each option describes adding a trailing newline at end-of-file, defaults to true, and includes a cautionary note against disabling it. Changes are documentation-only; no code or method signatures were modified.

Suggested reviewers

• arendjr
• siketyan

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically describes the main change: documenting the formatter.trailingNewline configuration option.
Description check	✅ Passed	The description relates to the changeset by referencing the corresponding biome PR that introduced the feature being documented.

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

src/content/docs/reference/configuration.mdx (1)

654-654: Use consistent default value format.

The default value format "> Defaults to true." differs from the established convention used throughout this document. All other defaults use the format "> Default: value" (see lines 51, 175, 182, 205, 242, etc.).

Suggested format

Change all instances from:

> Defaults to true.

To:

> Default: `true`

This makes the format consistent with the rest of the document and properly formats the boolean value as code.

Also applies to: 896-896, 1105-1105, 1251-1251, 1328-1328, 1403-1403, 1569-1569

📜 Review details

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📥 Commits

Reviewing files that changed from the base of the PR and between 2b31ed4 and 91c6e67.

📒 Files selected for processing (1)

• src/content/docs/reference/configuration.mdx

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