message: WIP: Document Semaphore
diff: @@ -7,6 +7,13 @@ import { ImmutableQueue } from "../Support/ImmutableQueue"
  import * as T from "./deps"
  import { State, Entry, assertNonNegative, Acquisition } from "./state"
  +/**
  + * An asynchronous semaphore, which is a generalization of a mutex. Semaphores
  + * have a certain number of permits, which can be held and released
  + * concurrently by different parties. Attempts to acquire more permits than
  + * available result in the acquiring fiber being suspended until the specified
  + * number of permits become available.
  + **/
  export class Semaphore {
  constructor(private readonly state: Ref<State>) {
  this.loop = this.loop.bind(this)
  