Small improvements to the documentation based on Sphinx HTML doc output.
Fixes: 14b8f0bbe519 ("doc: add BPF library guide")
Fixes: b901d928361c ("bpf: support packet data load instructions")
Cc: stable@dpdk.org
Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>