update README.md with instructions on how to use the solo mining mode

Author: lucasbalieiro

pool-apps/pool/README.md

@@ -84,4 +84,26 @@ Run the Pool (example using hosted Sv2 TP):
 ```bash
 cd pool-apps/pool
 cargo run -- -c config-examples/pool-config-hosted-sv2-tp-example.toml
-``` 
+```
+
+## Solo Mining Mode
+
+The solo mining mode is computed during runtime and expects that the user_identity value to be crafted in specific patterns.
+Enable solo mining by adding to your config. If the `user_identity` any of the patterns, the pool continues with the payout to the pool. If the `user_identity` matches the magic bytes: `sri` but the pattern is malformed we send a `OpenMiningChannelError`.
+### User Identity Patterns
+
+Miners must specify their payout mode via `user_identity`:
+
+| Pattern | Mode | Description |
+|---------|------|-------------|
+| `sri/donate/worker_name` | Pool | Full reward goes to pool |
+| `sri/solo/payout_address/worker_name` | Solo | Full reward goes to miner's address |
+| `bc1qtzqxqaxyy6lda2fhdtp5dp0v56vlf6g0tljy2x` | Solo | Full reward goes to miner's address |
+| `sri/donate/percentage/payout_address/worker_name` | Donate | Pool gets %, miner gets remainder |
+
+### Error Scenarios
+
+| Error Code | Cause |
+|------------|-------|
+| `invalid-user-identity` | Pattern doesn't match expected format |
+