Flow should not need capnp (ipc* does); ~Same changes made to flow/same-stuff also applied here (details omitted); highlight: manual workflow runnability; highlight: create tarball with docs and landing page which also hugely speeds up the artifact generation. Minor tweak for consistency in make arg order. Added TODO regarding how our CMake script should be able to determine jemalloc-prefix by itself, though giving it manually is certainly supported too. Renamed pipeline a bit (it is Flow-IPC; might as well keep "branding" consistent.

Flow should not need capnp (ipc* does); ~Same changes made to flow/same-stuff also applied here (details omitted); highlight: manual workflow runnability; highlight: create tarball with docs and landing page which also hugely speeds up the artifact generation. Minor tweak for consistency in make arg order. Added TODO regarding how our CMake script should be able to determine jemalloc-prefix by itself, though giving it manually is certainly supported too. Renamed pipeline a bit (it is Flow-IPC; might as well keep "branding" consistent. #17