whitepaper: Add information about eBPF based observability options

[bwplotka]

Idea came after our final 1.0 community review period:

eBPF is a revolutionary technology that can run sandboxed programs in the Linux kernel without changing kernel source code or loading a kernel module. With some creativity, it can help us achieve the long-time dream of observing systems without adding extra instrumentation. Even though the possibilities are endless, eBPF is not that popular. We'd like to tell our readers how eBPF and related tools can be a game-changer in the Observability space and why they're still not that popular.

[PrateekKumar1709]

Hi @bwplotka, I'd like to contribute to this issue if it's still available. Please let me know if I can proceed. Thanks!