Tweak README

README.md

@@ -86,17 +86,6 @@ overview.
 
 ## Building
 
-A native build of asciinema requires the Rust toolchain (1.82 or later) with
-Cargo. In a local checkout the recommended way to get it is the Nix dev shell,
-which provides the complete toolchain and just works:
-
-```sh
-nix develop
-```
-
-If you don't use Nix, install Rust with Cargo via your system package manager
-or [rustup](https://rustup.rs/).
-
 To download the source code, build the asciinema binary, and install it in
 `$HOME/.cargo/bin` in one go run:
 
@@ -104,14 +93,31 @@ To download the source code, build the asciinema binary, and install it in
 cargo install --locked --git https://github.com/asciinema/asciinema
 ```
 
-Then, ensure `$HOME/.cargo/bin` is in your shell's `$PATH`.
+This requires the Rust toolchain (1.82 or later) with Cargo, installed via your
+system package manager or [rustup](https://rustup.rs/).
 
-Alternatively, you can manually download the source code and build the asciinema
-binary with:
+Once installed, ensure `$HOME/.cargo/bin` is in your shell's `$PATH`.
+
+Alternatively, you can build from a local checkout. First download the source
+code:
 
 ```sh
 git clone https://github.com/asciinema/asciinema
 cd asciinema
+```
+
+The recommended way to get the toolchain is the Nix dev shell, which provides
+everything needed and just works:
+
+```sh
+nix develop
+```
+
+If you don't use Nix, you need Rust with Cargo, as above.
+
+Then build the binary with:
+
+```sh
 cargo build --release
 ```
 
@@ -140,7 +146,8 @@ generation (3.x) of the asciinema CLI, written in Rust.
 The previous generation (2.x), written in Python, can be found in the `python`
 branch.
 
-For toolchain setup and build instructions, see [Building](#building).
+For toolchain setup and build instructions, see [Building](#building). Run the
+test suite with `cargo test`.
 
 If you'd like to propose or submit any changes, please read the
 [contribution guidelines](CONTRIBUTING.md) first.