Make README better

[boundless-forest]

I found some issues concerning this README, FYI.

1. Ormp -> ORMP

2. There are a few places that can be improved in this chapter:

• These two references refer to the root url of this root. It means nothing. Change them to the correct tutorials or remove them. Most of the ormp runner don't need to run their own indexer, if I understand correctly.
• Create a table to record all the oracle, subapi, ormp endpoints and add note about how to choose between them. Please make it clear, I cannot run this pipe successfully folloing this README guide.
• "you can use *-indexer-oracle-endpoint or *-indexer-endpoint these are same, *-indexer-oracle-endpoint has higher priority", Suggest keeping one of them, lots of configs in this tool, please make the meaning of the command argument meaning as clear as possible.
• Suggest adding note about what does the Oracle relay and Relayer relay do?
• Realyer -> Relayer