Update the 'connecting to testnet' example

[Dhaiwat10]

As mentioned in this PR's conversation, the example on the page itself demonstrates initializing a wallet on the testnet and does not actually interact with any contracts on the testnet or with the testnet node itself.

I believe this example should show users how they can connect to and interact with a live beta-5 contract.

[arboleya]

Could we reuse another example we already have, only changing the node URL to point to live/beta5?

[Dhaiwat10]

I'm not aware of any. If there is one, we can re-use. I'll investigate this

[petertonysmith94]

@Dhaiwat10 did you investigate this one?