[Docs] Add link to PackagingCon talk (#1112)

[skip azp]

Author: giordano

docs/src/index.md

@@ -62,3 +62,4 @@ BinaryBuilder has been covered in some videos, you may want to check them out if
 * [BinaryBuilder.jl - The Subtle Art of Binaries That Just Work](https://www.youtube.com/watch?v=3IyXsBwqll8): JuliaCon 2020 workshop by Elliot Saba and Mosè Giordano to guide users through the use of BinaryBuilder (2020-07-25)
 * [Your first BinaryBuilder.jl recipe with Julia](https://www.youtube.com/watch?v=7fkNcdbt4dg): live building by Miguel Raz Guzmán Macedo (2021-04-07)
 * [BinaryBuilder.jl — The Subtle Art of Binaries That "Just Work"](https://bbb.dereferenced.org/playback/presentation/2.3/75a49eebcb63d6fee8c55417ea7cc51768d86f3d-1621065511930): AlpineConf 2021 talk by Elliot Saba and Mosè Giordano, starts at 4:19:00 (2021-05-15)
+* [BinaryBuilder.jl — Using Julia's Pkg to deliver binary libraries](https://www.youtube.com/watch?v=S__x3K31qnE): PackagingCon 2021 talk by Mosè Giordano & Elliot Saba (2021-11-10)