[No QA] Update help docs for Release 1: Commuter Mileage Exclusions (fixed distance)

[MelvinBot]

Explanation of Change

Documents the Release 1 scope of Commuter Mileage Exclusions: admins can enable Exclude commutes on a Control workspace under Distance Rates > Settings and choose Exclude a fixed distance per claim, which subtracts a configured distance from each eligible route-based claim (clamped at zero). When any exclusion is enabled, only Map and GPS distance methods are available.

Two existing help articles are updated (no new article — this is an extension of existing distance rate configuration and distance expense creation):

• docs/articles/new-expensify/workspaces/Set-distance-rates.md — adds an "Exclude commutes from distance expenses" section covering navigation to Distance Rates > Settings, the two method options, configuring the fixed distance, the per-claim/non-retroactive behavior, and the Map/GPS-only restriction.
• docs/articles/new-expensify/reports-and-expenses/Distance-Expenses.md — notes that Manual and Odometer entry are hidden when an exclusion is active, adds a "How commute exclusions affect Distance expenses" section explaining the confirmation screen, receipt, and system message, and adds two FAQ entries.

This implements the Release 1 help site updates scoped in Expensify/Expensify#631147.

Fixed Issues

$ https://github.com/Expensify/Expensify/issues/631147
PROPOSAL:

Tests

// TODO: The human co-author must fill out the tests you ran before marking this PR as "ready for review".
// Please describe what tests you performed that validate your change worked.

• Verify that no errors appear in the JS console

Offline tests

N/A — documentation-only change.

QA Steps

// TODO: The human co-author must fill out the QA tests you ran before marking this PR as "ready for review".
// Please describe what QA needs to do to validate your changes and what areas they need to test for regressions.

• Verify that no errors appear in the JS console

PR Author Checklist

• I linked the correct issue in the ### Fixed Issues section above

Screenshots/Videos

Documentation-only change — no UI screenshots. The Set Distance Rates article includes a non-rendered screenshot placeholder for the new Settings page once Release 1 ships.

[OSBotify]

A preview of your ExpensifyHelp changes have been deployed to https://7c68f761.helpdot.pages.dev ⚡️

Updated articles:

• articles/new-expensify/reports-and-expenses/Distance-Expenses
• articles/new-expensify/workspaces/Set-distance-rates