Implement Range Requests

[Dimava]

Resolves #19

[suside]

This implementation will fail when Range: bytes=0- is sent (chrome).
Im testing this currently with:

    const [start = 0, end = file.size] = range
        .split('=') // ["Range: bytes", "0-100"]
        .at(-1)! // "0-100"
        .split('-') // ["0", "100"]
        .filter(str => str.length)
        .map(Number) // [0, 100]