update packages, doc for licenses

.dockerignore

@@ -2,3 +2,4 @@
 node_modules/
 out/
 public/static/lang
+cors_proxy/
\ No newline at end of file

src/data/README.md

+the file "licenses.json" is generated with:
+
+`npx license-checker --json --relativeLicensePath --excludePrivatePackages --out ./src/data/licenses.json`
+
+This is usually done by using the npm script `npm run prebuild` which is invoked on relevant build actions