Replace "decodeFromInputVideoDevice" mentions with "decodeOnceFromVideoDevice"
Replace "decodeFromInputVideoDevice" mentions with "decodeOnceFromVideoDevice"

decodeFromInputVideoDevice is marked as deprecated in src/browser/BrowserCodeReader.ts, so replacing mentions of it in README with the replacement decodeOnceFromVideoDevice
zxing-js/library,zxing-js/library,zxing-js/library