CDK: rename uLxLy STB page

Author: hsutaiyu

docs/cdk/architecture/ulxly-stb.md …s/cdk/architecture/staking-the-bridge.mddocs/cdk/architecture/ulxly-stb.md renamed to docs/cdk/architecture/staking-the-bridge.md docs/cdk/architecture/ulxly-stb.md renamed to docs/cdk/architecture/staking-the-bridge.md

@@ -89,7 +89,7 @@ nav:
       - Architecture:
         - CDK rollup: cdk/architecture/cdk-zkevm.md
         - CDK validium: cdk/architecture/cdk-validium.md
-        - Unified bridge - STB: cdk/architecture/ulxly-stb.md
+        - Unified bridge - STB: cdk/architecture/staking-the-bridge.md
       - Specification:
         - Validium vs rollup: cdk/spec/validium-vs-rollup.md
       - Glossary: