tutorial: begin documenting the network API
tutorial: begin documenting the network API

Begin documenting Seastar's network API, demonstrating a TCP server which
accepts connections, and writes responses.

There's still more content missing in this introductory chapter, and a
lot more details we'll need to cover in later chapters, but at least we're
starting to demonstrate things a little more interesting than "hello world" :-)

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@cloudius-systems.com>

sjperkins/seastar,cloudius-systems/seastar,dreamsxin/seastar,scylladb/scylla-seastar,dreamsxin/seastar,avikivity/seastar,kjniemi/seastar,dreamsxin/seastar,scylladb/seastar,cloudius-systems/seastar,scylladb/scylla-seastar,syuu1228/seastar,kjniemi/seastar,avikivity/seastar,scylladb/scylla-seastar,syuu1228/seastar,syuu1228/seastar,sjperkins/seastar,kjniemi/seastar,scylladb/seastar,avikivity/seastar,cloudius-systems/seastar,scylladb/seastar,sjperkins/seastar