remove redundant list of videos

I will be making significant updates to list in the main readme and
there is no point in maintaining two lists.

Signed-off-by: Phill Kelley <[email protected]>

Author: Paraphraser

docs/index.md

@@ -29,16 +29,3 @@ Welcome to IOTstack:
 !!! cite inline end "Full site page listing"
 
     {nav}
-
-## introduction to IOTstack - videos
-
-These are from 2019 and 2020. Though IOTstack has changed a bit, they are still
-a great introduction.
-
-Andreas Spiess Video #295: Raspberry Pi Server based on Docker, with VPN, Dropbox backup, Influx, Grafana, etc: IOTstack
-
-[![#295 Raspberry Pi Server based on Docker, with VPN, Dropbox backup, Influx, Grafana, etc: IOTstack](http://img.youtube.com/vi/a6mjt8tWUws/0.jpg)](https://www.youtube.com/watch?v=a6mjt8tWUws)
-
-Andreas Spiess Video #352: Raspberry Pi4 Home Automation Server (incl. Docker, OpenHAB, HASSIO, NextCloud)
-
-[![#352 Raspberry Pi4 Home Automation Server (incl. Docker, OpenHAB, HASSIO, NextCloud)](http://img.youtube.com/vi/KJRMjUzlHI8/0.jpg)](https://www.youtube.com/watch?v=KJRMjUzlHI8)