Improve documentation

[fydelio]

The documentation needs improvement on the following topics

• How to properly handle errors (NotFoundException, ChecksumException, FormatException)
• How to light the torch
• How to get the videoInputDevices (like the different lenses)
• How to get the selected videoInputDevice (e.g. to update the select box with the selected box)
• How to properly select the environment camera (somehow with regex ?!?)
• How to stop the video stream
• How to stop the barcode processing temporarily (e.g. while submitting the result from a positive QR-read to the server)
• the method decodeFromVideoDevice now takes a control parameter. What does it allow and how can I further control the behaviour of the scanner?
• BrowserMultiFormatReader: How to define which barcodes are accepted.

This is a new issue, as requested by @odahcam in issue #42

[minusdavid]

Also:

• how to use decodeOnceFromVideoDevice
• how to use controls.stop()
• how to use this code within a function and not from the top level of a script
• how to run this code synchronously from a button press