* runtime: use babe as randomness source

* runtime: fix randomness api

* bridges: fix random_seed

* parachains: use mock TestRandomness from frame_support_test

* parachains: use mock TestRandomness from frame_support_test

* runtime: update randomness source in test-runtime

* runtime: remove unused import

* parachains: add todo to audit usage of randomness api

* "Update Substrate"

Co-authored-by: parity-processbot <>

* Add instructions.

* Squashed 'bridges/' content from commit 345e84a21

git-subtree-dir: bridges
git-subtree-split: 345e84a2146b56628e9888c9f5e129cb40e868a9

* Remove bridges workspace file to avoid confusing Cargo.

* Add some bridges primitives to Polkadot workspace.

* Improve docs.