Update sovereign-sdk and use out-of-tree subxt

Author: gabriele-0201

.gitignore

@@ -0,0 +1,3 @@
+zombienet/
+target/
+/demo/demo-rollup/demo_data

README.md

@@ -1,8 +1,44 @@
+# Instruction to test demo-rollup
+
+2 steps are required before:
++ build sugondat-chain
++ Adjust the PATHs to polkadot and sugondat-chain for zomienet
+
+Now you can launch 2 polkadot validators and one sugondat-chain collator
+``` sh
+./zombienet.sh
+```
+
+launch the demo rollup with:
+``` sh
+cd demo/demo-rollup
+cargo run
+```
+
+execute the test
+```
+cd demo/demo-rollup
+./test_create_token.sh
+```
+
+You should see at the end that a batch of two transactions was correctly pushed in the DA, fetched back and then executed in the rollup to create and mint 4000 new tokens
+
+If you want to re-run zombienet and the demo rollup remember token
+
+``` sh
+rm -r zombienet
+cd demo/demo-rollup
+# clean the ledger db
+make clean
+```
+
 # Usage
 
 To launch the testnet you should use `zombienet`.
 
     # First, make sure that the binaries `polkadot` and `sugondat-node` are in your PATH.
+    # If you're using a polkadot binary >=1.0.0 then you need also the binaries 
+    # polkadot-execute-worker and polkadot-prepare-worker
     export PATH=/Users/pepyakin/dev/parity/polkadot/target/release/:$PATH
     export PATH=/Users/pepyakin/dev/parity/sugondat-chain/sugondat-chain/target/release/:$PATH