Update the brilirs documentation

docs/tools/brilirs.md

@@ -3,7 +3,7 @@ Fast Interpreter in Rust
 
 The `brilirs` directory contains a fast Bril interpreter written in [Rust][].
 It is a drop-in replacement for the [reference interpreter](interp.md) that prioritizes speed over completeness and hacakability.
-It only [core Bril](../lang/core.md), except for functions, and the [floating point](../lang/float.md) extension.
+`brilirs` implements [core Bril](../lang/core.md), [SSA][], [memory][], and [floating point][float] extensions.
 
 Read [more about the implementation][blog], which is originally by Wil Thomason and Daniel Glus.
 
@@ -13,7 +13,10 @@ Like any other Rust project, building is easy:
 
 Run a program by piping a JSON Bril program into it:
 
-    cargo run < myprogram.json
+    bril2json < myprogram.bril | cargo run
 
 [rust]: https://www.rust-lang.org
+[ssa]: ../lang/ssa.md
+[memory]: ../lang/memory.md
+[float]: ../lang/float.md
 [blog]: https://www.cs.cornell.edu/courses/cs6120/2019fa/blog/faster-interpreter/