Fix image links of wasm-bpf.md

[WoodHolz]

Description

Fixes # 32

Type of change

• Bug fix (non-breaking change which fixes an issue)

- <img src=https://ebpf.io/static/overview-3c0c9cd2010cb0b7fdc26e5e17d99635.png width=60% />
+ <img src=https://github.com/ebpf-io/ebpf.io-website/blob/main/content/static-pages/what-is-ebpf/overview.png width=60% alt="eBPF Overview" />

- <img src=https://ebpf.io/static/kernel_arch-c0be6286222dcd0e6e45250d2d9a87fd.png width=60% />
+ <img src=https://github.com/ebpf-io/ebpf.io-website/blob/main/content/static-pages/what-is-ebpf/kernel-arch.png width=60% />

- <img src=https://ebpf.io/static/libbpf-ee03b2f4d79b197554fa00671e67129d.png width=60% />
+ <img src=https://github.com/ebpf-io/ebpf.io-website/blob/main/content/static-pages/what-is-ebpf/libbpf.png width=60% />