docs enhancement: Hedera EVM versus Ethereum EVM

[theekrystallee]

The goal would be to separate differences between the Hedera EVM & Ethereum EVM that are more likely to apply to

1. Ethereum developers coming to Hedera: Cross-deploying or migrating. Mainly ECDSA focused. These devs/apps may be limited in their ability to serve existing ecosystem accounts with ED25519 keys (majority today)
2. Hedera native developers adding smart contract functionality: ED25519 focused and serving ecosystem accounts with those keys. May need to expand to another chain that only supports ECDSA

@ed-marquez's initial pass at capturing the differences that apply to group (1) above (Ethereum developers coming to Hedera). Please share feedback and thoughts on items that may be in progress, not applicable, or missing.

• No EC recover for ED25519 (coming soon: isAuthorizedRaw/isAuthorized)
• No way to burn HBAR (to be implemented at some point in the future)
• No support for contract snapshots
  • aka. No support for Fixture functionality in HardHat
• Signer returned by ECRECOVER after key rotation
• Decimals (8 on Hedera vs 18 on Ethereum)
• receive() function does not fire when HBAR is sent to a contract, so you have to create a manual function that’s called instead