docs: update import path in sdk

Author: MarcosNicolau

docs/3_guides/1_SDK_how_to.md

@@ -24,7 +24,7 @@ To get the SDK up and running in your project, you must first import it
 
 ```rust
 use aligned_sdk::common::types::{PriceEstimate, AlignedVerificationData, Network, ProvingSystemId, VerificationData};
-use aligned_sdk::sdk::{estimate_fee, submit_and_wait, get_nonce_from_ethereum};
+use aligned_sdk::verification_layer::{estimate_fee, submit_and_wait, get_nonce_from_ethereum};
 ```
 
 And then you can do a simple call of, for example, `get_nonce_from_ethereum`