docs: link llms.txt and llms-full.txt for AI discovery

Author: bug3

README.md

@@ -207,6 +207,13 @@ Install the [SQL Formatter VSCode](https://marketplace.visualstudio.com/items?it
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+## For LLMs
+
+Two machine-readable summaries are maintained for AI consumption, following the [llms.txt](https://llmstxt.org) convention:
+
+- [llms.txt](llms.txt) - curated API reference and usage guide
+- [llms-full.txt](llms-full.txt) - full packed source, auto-generated on each push
+
 ## License
 
 [MIT](https://github.com/bug3/sql-render/blob/master/LICENSE)