#22403: docs: add SMS Gateway to community plugins

## Summary Adds [SMS Gateway](https://github.com/zacharypodbela/openclaw-sms-gateway) to the community plugins page. - **npm**: `openclaw-sms-gateway` - **repo**: https://github.com/zacharypodbela/openclaw-sms-gateway - **description**: Enable OpenClaw to send and receive SMS via an Android phone - **install**: `openclaw plugins install openclaw-sms-gateway` ### Checklist per listing requirements - [x] Package published on npmjs - [x] Source code hosted on GitHub (public) - [x] Repository includes docs and issue tracker - [x] Active maintenance signal <!-- greptile_comment --> <h3>Greptile Summary</h3> Adds the [SMS Gateway](https://github.com/zacharypodbela/openclaw-sms-gateway) plugin to the community plugins documentation page. The entry follows the documented candidate format and includes all required fields (name, description, npm package, repo URL, install command). - The plugin listing itself is well-formed and meets the documented quality bar checklist. - Minor structural nit: the new `## Community plugins` section heading duplicates the page's top-level `# Community plugins` title, which may cause confusing TOC/sidebar entries in rendered docs. <h3>Confidence Score: 4/5</h3> - This is a docs-only change that adds a community plugin listing — safe to merge with a minor heading tweak. - The change is a small, docs-only addition that correctly follows the documented format. The only issue is a duplicate section heading which is cosmetic, not functional. - No files require special attention — this is a single documentation file change. _{Last reviewed commit: 0be7d0e} <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->