Clarify license translation policy and link the OpenAtom Chinese translation

[tisonkun]

The licensing FAQ explains that translations are for convenience and that the English text is authoritative, but it does not explicitly state that the ASF endorses no translation. Add a separate FAQ entry clarifying that position, and link it from the licenses index and the introductory text on the Apache License 2.0 page. This documentation clarification stands on its own, without referring to OpenAtom or any other translation publisher.

Then add OpenAtom's Chinese translation as a convenience reference, with an explanation that the publisher arranged its own legal review and that the ASF has neither formally reviewed nor endorsed the translation. OpenAtom supplied the canonical URL and confirmed its acceptance of this position in the follow-up discussion. The existing translation FAQ entry and the license text are unchanged.

This PR combines two changes for review and preview, in separate commits. It can be split into two PRs if preferred:

1. Clarify the ASF's general policy on license translations and add links to that guidance from the two license pages, with no OpenAtom information (1e611f137).
2. Add the OpenAtom translation reference and the accompanying explanation of publisher legal review and non-endorsement (ee63bf655).

The first part can be reviewed and merged independently of whether the ASF chooses to list third-party translations. The second part would build on it.

Discussion and source:

• Original legal-discuss discussion and proposed FAQ
• OpenAtom's response and canonical URL
• OpenAtom's Chinese translation

Preview:

• New FAQ entry
• Licenses index
• Apache License 2.0 page

Validation:

• git diff --check passes.
• Verified that the existing translation FAQ entry and the license body are unchanged, and that the new FAQ anchor, table-of-contents entry, and both incoming links agree.
• The canonical translation URL returns HTTP 200 and includes a disclaimer and a link to the ASF's English original.
• ASF Pelican build #31265 passed and published the staged site. Visually checked all three staged pages and followed both new license-page links to the FAQ entry.
• Reorganized the commits without changing the final file tree; the published preview and prior rendering checks apply to the same content.