Updated REAMDE.md and BRIDGES.md (inspired by original https://github…

….com/paritytech/polkadot/blob/d22eb62fe40e55e15eb91d375f48cc540d83a47e/BRIDGES.md)

BRIDGES.md

@@ -0,0 +1,88 @@
+# Using Parity Bridges Common dependency (`git subtree`).
+
+In `./bridges` sub-directory you can find a `git subtree` imported version of:
+[parity-bridges-common](https://github.com/paritytech/parity-bridges-common/) repository.
+
+(For regular Cumulus contributor 1. is relevant) \
+(For Cumulus maintainer 1. and 2. are relevant) \
+(For Bridges team 1. and 2. and 3. are relevant)
+
+# 1. How to fix broken Bridges code?
+
+To fix Bridges code simply create a commit in current (`Cumulus`) repo. Best if
+the commit is isolated to changes in `./bridges` sub-directory, because it makes
+it easier to import that change back to upstream repo.
+
+(Any changes to `bridges` subtree require Bridges team approve and they should manage backport to Bridges repo)
+
+
+# 2. How to pull latest Bridges code to the `bridges` subtree
+(in practice)
+```
+cd <cumulus-git-repo-dir>
+
+# this will update new git branches from bridges repo
+# there could be unresolved conflicts, but dont worry,
+# lots of them are caused because of removed unneeded files with patch step,
+./scripts/bridges_update_subtree.sh fetch
+
+# so, after fetch and before solving conflicts just run patch,
+# this will remove unneeded files and checks if subtree modules compiles
+./scripts/bridges_update_subtree.sh patch
+
+# if there are conflicts, this could help,
+# this removes locally deleted files at least (move changes to git stash for commit)
+./scripts/bridges_update_subtree.sh merge
+
+# (optional) when conflicts resolved, you can check build again - should pass
+# also important: this updates global Cargo.lock
+./scripts/bridges_update_subtree.sh patch
+
+# add changes to the commit, first command `fetch` starts merge,
+# so after all conflicts are solved and patch passes and compiles,
+# then we need to finish merge with:
+git merge --continue
+````
+
+# 3. How to pull latest Bridges code or contribute back?
+(in theory)
+
+Note that it's totally fine to ping the **Bridges Team** to do that for you. The point
+of adding the code as `git subtree` is to **reduce maintenance cost** for Cumulus/Polkadot
+developers.
+
+If you still would like to either update the code to match latest code from the repo
+or create an upstream PR read below. The following commands should be run in the
+current (`polkadot`) repo.
+
+1. Add Bridges repo as a local remote:
+```
+$ git remote add -f bridges git@github.com:paritytech/parity-bridges-common.git
+```
+
+If you plan to contribute back, consider forking the repository on Github and adding
+your personal fork as a remote as well.
+```
+$ git remote add -f my-bridges git@github.com:tomusdrw/parity-bridges-common.git
+```
+
+2. To update Bridges:
+```
+$ git fetch bridges master
+$ git subtree pull --prefix=bridges bridges master --squash
+````
+
+We use `--squash` to avoid adding individual commits and rather squashing them
+all into one.
+
+3. Clean unneeded files here:
+```
+./bridges/scripts/verify-pallets-build.sh --ignore-git-state --no-revert
+```
+
+4. Contributing back to Bridges (creating upstream PR)
+```
+$ git subtree push --prefix=bridges my-bridges master
+```
+This command will push changes to your personal fork of Bridges repo, from where
+you can simply create a PR to the main repo.

parachains/runtimes/bridge-hubs/README.md

@@ -35,41 +35,3 @@ or
 # BridgeHubPolkadot
 zombienet-linux --provider native spawn ./zombienet/examples/bridge_hub_polkadot_local_network.toml
 ```
-
-----
-## Git subtree `./bridges`
-
-Add Bridges repo as a local remote and synchronize it with latest `master` from bridges repo:
-
-### How to update `bridges` subtree
-```
-cd <cumulus-git-repo-dir>
-# this will update new git branches from bridges repo
-# there could be unresolved conflicts, but dont worry,
-# lots of them are caused because of removed unneeded files with patch step :)
-# so before solving conflicts just run patch
-./scripts/bridges_update_subtree.sh fetch
-# this will remove unneeded files and checks if subtree modules compiles
-./scripts/bridges_update_subtree.sh patch
-# if there are conflicts, this could help, removes locally deleted files at least
-# (but you can also do this manually)
-./scripts/bridges_update_subtree.sh merge
-# when conflicts resolved, you can check build again - should pass
-# also important: this updates global Cargo.lock
-./scripts/bridges_update_subtree.sh patch
-````
-We use `--squash` to avoid adding individual commits and rather squashing them
-all into one.
-Now we use `master` branch, but in future, it could change to some release branch/tag.
-
-### How was first time initialized (does not need anymore)
-```
-cd <cumulus-git-repo-dir>
-git remote add -f bridges git@github.com:paritytech/parity-bridges-common.git
-# (ran just only first time, when subtree was initialized)
-git subtree add --prefix=bridges bridges master --squash
-# remove unnecessery files
-./scripts/bridges_update_subtree.sh patch
-./scripts/bridges_update_subtree.sh merge
-git commit --amend
-```