low: proposal pool single and pool static chaining factory

[Slava Bereza]

pool.single(async () => {

})

// or

pool(async () => {

}).single()

// Will be same result

[Slava Bereza]

pool.debounce(300).single().flow(async () => {});
// ok

[Slava Bereza]

Added to "the stream of conciseness 0.7+ roadmap"