Add missing pictures

[eptak]

Lot of pictures are missing from the documentation. Seems it was in an old S3 bucket: https://s3.amazonaws.com/cloudfront-mydevices-wordpress/wp-content/uploads/20170516152527/Objenius-SPOT-Portal-sign-in.png

Brent has a backup of pictures on his drive: https://drive.google.com/drive/folders/1H8ol80RPIPdEbcqrq_C3ScCb7Ac1iIRo?usp=sharing

We'll need to write a small script to fix that :

1. Find all wp-content/uploads occurences
2. Find match for the picture (dash=space)
3. Rename picture accordingly into a temporary folder
4. Upload all pictures from the folder above
5. Fix all img src
6. (opt) Check that all image are uploaded, flag missing ones
7. Repeat until happy

[drasko]

I do not know if this is related, but lot of images missing here: https://github.com/myDevicesIoT/cayenne-docs/blob/master/docs/LORA.md#cayenne-low-power-payload