[chore] rename encoderSettings to formatConfigs

[chrisgervang]

Formats can be configured with the following passed into DeckAdapter.render({formatConfigs})

interface FormatConfigs {
  jpeg: {
    quality: number
  },
  webm: {
    quality: number
  }
  gif: {
    numWorkers: number,
    sampleInterval: number,
    width: number,
    height: number
    jpegQuality: number
  }
}

[coveralls]

Pull Request Test Coverage Report for Build 924180236

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 924111654:	0.0%
Covered Lines:	2
Relevant Lines:	2

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💛 - Coveralls