readme: add zero-to-install quick start, Arch deps, cross-repo links

README.md

@@ -3,10 +3,14 @@
 A [Git LFS custom transfer agent][custom-transfer] that backs large file storage with
 [IPFS](https://ipfs.tech), for use with [Radicle](https://radicle.xyz) repositories.
 
-This is the companion binary for the `rad lfs` support added to a
+This is the companion binary for the `rad lfs` support added in
-[fork of `heartwood`](../radicle-heartwood-lfs) (Radicle's core node/CLI). It is not meant to
+[**radicle-heartwood-lfs**](https://git.hswro.org/mab122/radicle-heartwood-lfs) (a fork of
-be invoked directly — `git lfs` spawns it automatically once a repository has been set up with
+Radicle's core node/CLI, `heartwood`). **Most people want to start there, not here** — that
-`rad lfs init`.
+repo has the full zero-to-usable setup guide. This repo is what you're reading if you want to
+build/understand the transfer agent on its own, or you're following a link back from there.
+
+`rad-lfs-transfer` is not meant to be invoked directly — `git lfs` spawns it automatically,
+once a repository has been set up with `rad lfs init` (from the fork above).
 
 [custom-transfer]: https://github.com/git-lfs/git-lfs/blob/main/docs/custom-transfers.md
 
@@ -26,9 +30,25 @@ Instead of a shared, seed-hosted LFS server, every peer uses their own local IPF
     looks up its `cid=` note, and fetches the content from your local IPFS daemon (which will
     pull it from the wider IPFS network if it isn't local yet).
 
-There is no central server anywhere in this design — see the companion `heartwood` fork's
+There is no central server anywhere in this design — see
-documentation for the full rationale and how `rad seed`/`rad unseed` tie IPFS pinning to
+[radicle-heartwood-lfs's `LFS-IPFS.md`](https://git.hswro.org/mab122/radicle-heartwood-lfs/src/branch/rad-lfs-ipfs/LFS-IPFS.md)
-Radicle's existing seeding lifecycle.
+for the full rationale and how `rad seed`/`rad unseed` tie IPFS pinning to Radicle's existing
+seeding lifecycle.
+
+## Dependencies
+
+On Arch Linux:
+
+```sh
+# To build and install
+sudo pacman -S --needed rust git
+
+# To actually use it (not needed to build/install — see "Requirements" below)
+sudo pacman -S --needed kubo
+```
+
+On other distributions, install a Rust toolchain (e.g. via [rustup](https://rustup.rs)), Git,
+and — only when you want to use LFS, not to build this — [Kubo](https://docs.ipfs.tech/install/).
 
 ## Requirements
 
@@ -37,16 +57,27 @@ Radicle's existing seeding lifecycle.
   running when `git lfs push`/`pull` tries to use it, you'll get a clear error telling you to
   start one (`ipfs daemon`) — nothing fails silently, and nothing about building or installing
   this binary requires IPFS to be present at all.
-- [Git LFS](https://git-lfs.com) installed (`git-lfs` on your `PATH`).
+- [Git LFS](https://git-lfs.com) installed (`git-lfs` on your `PATH`) — `git-lfs` package on
+  Arch (`sudo pacman -S --needed git-lfs`).
 
 ## Build & install
 
 ```sh
+git clone ssh://git@git.hswro.org:9022/mab122/radicle-lfs-transfer.git
+cd radicle-lfs-transfer
 cargo install --path .
 ```
 
-This installs the `rad-lfs-transfer` binary to `~/.cargo/bin` (make sure that's on your
+This installs the `rad-lfs-transfer` binary to `~/.cargo/bin` by default — make sure that's on
-`PATH` — it's needed there so `git lfs` can find it once `rad lfs init` configures it).
+your `PATH`. If you're installing it alongside `radicle-heartwood-lfs` (the usual case), install
+it to that project's shared root instead so everything ends up in one place:
+
+```sh
+cargo install --path . --force --locked --root ~/.radicle
+```
+
+(You normally don't need to clone this repo separately at all for that — `radicle-heartwood-lfs`
+includes it as a git submodule and its own setup instructions cover installing both together.)
 
 ## Configuration