(Documentation) Update documentation

[Mad]

Needs diagrams, drawings and graphics (see the bridge repo)
https://l2beat.com/scaling/projects/arbitrum#contracts
https://github.com/FuelLabs/fuel-bridge/blob/main/docs/ARCHITECTURE.md

Needs a much better explanation of the entire architecture, including it’s bridging in relation to the security profile
https://l2beat.com/scaling/projects/arbitrum#risk-summary

No clear reference of the decimal adjustments and limitations:
https://github.com/FuelLabs/fuel-bridge/blob/main/docs/ARCHITECTURE.md#decimals-adjustment

Doesn’t characterize the bridge correctly as an arbitrary message passing bridge, it’s not just about moving funds, it’s also about moving messages.