Combine llms.txt generation with website data generation

- Move llms.txt generation into generate-website-data.mjs
- Remove standalone generate-llms-txt.mjs script
- Remove llms:generate npm script
- llms.txt now outputs to website/public/data/ alongside other generated files

package.json

@@ -7,7 +7,6 @@
   "scripts": {
     "start": "npm run build",
     "build": "node ./eng/update-readme.mjs",
-    "llms:generate": "node ./eng/generate-llms-txt.mjs",
     "contributors:add": "all-contributors add",
     "contributors:report": "node ./eng/contributor-report.mjs",
     "contributors:generate": "all-contributors generate",
@@ -18,7 +17,7 @@
     "skill:create": "node ./eng/create-skill.mjs",
     "website:data": "node ./eng/generate-website-data.mjs",
     "website:dev": "npm run website:data && npm run --prefix website dev",
-    "website:build": "npm run build && npm run website:data && node ./eng/generate-llms-txt.mjs website/public && npm run --prefix website build",
+    "website:build": "npm run build && npm run website:data && npm run --prefix website build",
     "website:preview": "npm run --prefix website preview"
   },
   "repository": {