Migrate Smart Contract course from Learnworlds

[Andyvargtz]

[Andyvargtz]

100% Content migrated from Leanworlds.

TODO:

• 2 pages to add:

• course/solidity-foundry/06-contract-standarization/03-interfaces.mdx
• course/solidity-foundry/07-erc20-smart-contracts/01-erc20-intro.mdx
• Migration to Developer Hub
• Access to Vercel builder-hub project-> Requested (pending)