README.md: several wishy-washy taglines

[trentmc]

At https://docs.oceanprotocol.com/ we see several wishy-washy taglines.

• Data Science: "we invite and engage all data scientists and machine learning specialists to discover Ocean Protocol"
• Predictoor: "Learn about Predictoor and how to make money with data science or by improve your trading edge with accurate signals"
• Data Farming Rewards: "Explore how you can earn OCEAN Rewards by Data Farming and publishing your assets on the Ocean Market"

None of these have punch. They should concisely summarize the benefits to the target demographic or of the toolset.