I Updated the /m/Sliderules Magazine Panel

I have updated the /m/Sliderules Magazine Panel.

• Some links have changed, particularly with ISRM's redesign
• Walter Shawlee's unfortunate passing has changed what is available on the Sphere Research site. You can still buy #Sliderules there at the updated link!
• There is new Slide Rule content on Youtube!

#Sliderules #Sliderule