Simplify generation of wallet address for new developers

[ctindogarus4f]

Description of the pull request (what is new / what has changed)

The process of creating a new wallet address can be overwhelming for a new developer on Elrond. There is no reason to force him to create an wallet via web wallet and then force him to derive the seed phrase from the web wallet to be able to use erdpy. Instead, we can create the wallet address directly with erdpy.

Did you test the changes locally ?

• [x] yes
• [ ] no

Which category (categories) does this pull request belong to?

• [ ] document new feature
• [x] update documentation that is not relevant anymore
• [ ] add examples or more information about a component
• [ ] fix grammar issues
• [ ] other

[ctindogarus4f]

any updates on this?