Address comments on libbpf.h API documentation

[dthaler](https://github.com/dthaler) reviewed [8 hours ago](https://github.com/microsoft/ebpf-for-windows/pull/4341#pullrequestreview-2757379340)
[include/bpf/libbpf.h](https://github.com/microsoft/ebpf-for-windows/pull/4341/files/c0c35f7194187bee9091ca8db16700bd1336cd80#diff-51005a88f9d069f59b4799b56c3a9430d710a514feea4ee723e63cddc50edcb2)
@@ -943,6 +943,34 @@ bpf_program__flags(const struct bpf_program* prog);
int
bpf_program__set_flags(struct bpf_program* prog, __u32 flags);

/**
* @brief Create BPF perfbuf manager.
Collaborator
@[dthaler](https://github.com/dthaler) dthaler 8 hours ago
Suggested change
* @brief Create BPF perfbuf manager.
* @brief Create BPF perfbuf manager for a specified BPF_PERF_EVENT_ARRAY map.
Any reason not to use the full phrase that libbpf.h has?

@shankarseal Reply...
[include/bpf/libbpf.h](https://github.com/microsoft/ebpf-for-windows/pull/4341/files/c0c35f7194187bee9091ca8db16700bd1336cd80#diff-51005a88f9d069f59b4799b56c3a9430d710a514feea4ee723e63cddc50edcb2)
/**
* @brief Create BPF perfbuf manager.
*
* @param[in] map_fd File descriptor to perf event array map.
Collaborator
@[dthaler](https://github.com/dthaler) dthaler 8 hours ago
libbpf.h has description "FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF code to send data over to user-space". Is there a reason to use different language here?

Same question for other new descriptions.