Async, custom, inline snapshot matcher in jest

Documents how to make custom inline snapshot matchers work.

Fix:

jest-async-inlinesnapshot/index.test.js

Lines 4 to 7 in 6416947

	// Jest uses the stacktraces to find the callsite.
	// For async stacktraces it'll point to the wrapped call
	// i.e. every `toMatchSpeechInlineSnapshotAsync` will point to the same call triggering "Jest: Multiple inline snapshots for the same call are not supported."
	this.error = new Error();