docs: adding Pluto readme

[curtis-h]

https://github.com/hyperledger/identus-edge-agent-sdk-ts/issues/260

Starting a README for Pluto, trying to better explain the options available.

[github-actions[bot]]

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[coveralls]

Pull Request Test Coverage Report for Build 11615138137

Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 72.549%

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Totals
Change from base Build 11613312315:	0.0%
Covered Lines:	3523
Relevant Lines:	4647

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💛 - Coveralls