Add examples.fsproj with Oryx.ThothJsonNet example

[da9l]

I've added a runnable Oryx.ThothJsonNet example based on the example in Readme.md.

IMLE (in my limited experience) Thoth makes a better job of showing what causes an error and it also makes it a lot easier to map strange json to sensible f# types.

I've set up the examples project to have project reference dependencies to all Oryx parts but paket dependencies to everything else.

Use or modify this PR as you find suitable.

[codecov[bot]]

Codecov Report

Merging #58 into master will not change coverage. The diff coverage is n/a.

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