docs(profile): present community infrastructure vision

[lin594]

Summary

• present E-Dialect first as an open-source community for reusable local-language digital infrastructure
• position 乡声万语 as the community's current flagship initiative, while leaving room for future initiatives
• connect the verified 万语校坊、乡声集盒 and 兴化语记 repositories into one practical workflow
• distinguish experimental intelligence modules from mature products
• add concrete contribution paths and concise governance, licensing, and data-boundary links

Deliberate exclusions

• no .profile repository: GitHub organization profiles use .github/profile/README.md
• no generic MIT badge because repositories have different license and content boundaries
• no empty or placeholder links
• no unverified scale claims or description of 兴化语记 as merely a demo

Verification

• git diff --check origin/main...HEAD
• verified all repository, documentation, governance, and Project docs(cla): pin ICLA v1.0 production identity #7 links
• confirmed the PR changes only profile/README.md

This PR is independent of CLA Assistant activation and should remain open for human review.