remove unused sub accounts and add readme file how to run relayer

[RustNinja]

Required for merge:

• [ ] pr-workflow-check / draft-release-check is ✅ success
• Other rules GitHub shows you, or can be read in configuration

Makes review faster:

• [ ] PR title is my best effort to provide summary of changes and has clear text to be part of release notes
• [ ] I marked PR by misc label if it should not be in release notes
• [ ] Linked Zenhub/Github/Slack/etc reference if one exists
• [ ] I was clear on what type of deployment required to release my changes (node, runtime, contract, indexer, on chain operation, frontend, infrastructure) if any in PR title or description
• [ ] Added reviewer into Reviewers
• [ ] I tagged(@) or used other form of notification of one person who I think can handle best review of this PR
• [ ] I have proved that PR has no general regressions of relevant features and processes required to release into production
• [ ] Any dependency updates made, was done according guides from relevant dependency
• Clicking all checkboxes
• Adding detailed description of changes when it feels appropriate (for example when PR is big)

[github-actions[bot]]

Pull reviewers stats

Stats of the last 30 days for composable:		User	Total reviews	Time to review	Total comments
	kkast	6	11h 20m))	0
	RustNinja	5	54m))	1
	dzmitry-lahoda	4	4h 2m))	0
	blasrodri	2	38m))	1
	vmarkushin	1	2h 43m))	0
	0xBrainjar2	1	7m))	0

[github-actions[bot]]

# run Composable node
nix run "github:ComposableFi/composable/refs/pull/4398/merge" --allow-import-from-derivation --extra-experimental-features "flakes nix-command" --no-sandbox --accept-flake-config --option sandbox relaxed

# run local Picasso DevNet (for CosmWasm development)
nix run "github:ComposableFi/composable/refs/pull/4398/merge#devnet-picasso" --allow-import-from-derivation --extra-experimental-features "flakes nix-command" --no-sandbox --accept-flake-config --option sandbox relaxed 

# CosmWasm on Substrate CLI tool
nix run "github:ComposableFi/composable/refs/pull/4398/merge#ccw" --allow-import-from-derivation --extra-experimental-features "flakes nix-command" --no-sandbox --accept-flake-config --option sandbox relaxed 

# run cross chain devnet with Dotsama and Cosmos nodes 
nix run "github:ComposableFi/composable/refs/pull/4398/merge#devnet-xc-fresh" --allow-import-from-derivation --extra-experimental-features "flakes nix-command" --no-sandbox --accept-flake-config --option sandbox relaxed 
# or same with docker
nix build "github:ComposableFi/composable/refs/pull/4398/merge#devnet-xc-image" --allow-import-from-derivation --extra-experimental-features "flakes nix-command" --no-sandbox --accept-flake-config --option sandbox relaxed \
&& docker load --input result && docker run -it --entrypoint bash devnet-xc:latest -c /bin/devnet-xc-fresh 

About nix