Add examples for interacting with tx service on docs.safe.global

[Uxio0]

Add examples for interacting with tx service on https://docs.safe.global/safe-core-api/service-architecture

• Creating a transaction and sending offchain signatures from the owners.
• Getting a transaction and executing it.
• Creating a message and sending offchain signatures.
• Getting last executed transaction.
• Batch Transactions (optional).
• Manage delegates.
• For documenting usage of the service we can give some alternatives:
  • https://github.com/safe-global/safe-eth-py/ (optional)
  • https://github.com/safe-global/safe-core-sdk (API Kit) (optional)
  • Simple curl calls

[Uxio0]

@falvaradorodriguez for this issue you can talk to @JagoFigueroa and check the Postman examples he has

[JagoFigueroa]

All good for me buenos señores 😄