docs: including sandbox diagrams in the sandbox section (#2573)

A while ago I've created diagrams as part of [this
issue](AztecProtocol/aztec-packages#1802) but
they were forgotten. In this PR I include them in the sandbox section.

docs/dev_docs/getting_started/sandbox.md

@@ -259,6 +259,9 @@ In this section, we created 2 instances of the `TokenContract` contract abstract
 
 We can see that each account has the expected balance of tokens.
 
+### Diagram of calling an unconstrained (view) function
+<img src="/img/sandbox_unconstrained_function.svg" alt="Unconstrained function call" />
+
 ## Creating and submitting transactions
 
 Now lets transfer some funds from Alice to Bob by calling the `transfer` function on the contract. This function takes 4 arguments:
@@ -346,6 +349,9 @@ That's it! We have successfully deployed a private token contract to an instance
 
 You can find the [complete tutorial code here](https://github.com/AztecProtocol/dev-rel/tree/main/tutorials/sandbox-tutorial/token).
 
+### Diagram of sending a transaction
+<img src="/img/sandbox_sending_a_tx.svg" alt="Sending a transaction" />
+
 ## Next Steps
 
 Here we showed how to interact with the sandbox, but didn't go into details on how to write your own contract or any relevant setup needed for it.