Updated README.md with information on syntax highlighting extensions.

PiperOrigin-RevId: 696177561
Change-Id: I9fbab638f3aecc0428032faad9096942eab7bf5a

README.md

diff --git a/README.md b/README.md
index 40e4f07..7d13d40 100644
--- a/README.md
+++ b/README.md
@@ -49,10 +49,15 @@
     instructions and instruction encodings of an ISA, and generate C++
     code for the instruction decoder for an MPACT-Sim simulator.
 
-    The tools are built automatically and the process is largly invisible when
+    The tools are built automatically and the process is largely invisible when
     using bazel with the appropriate build targets - see the tests in
     mpact/sim/decoder/test for examples.
 
+*   mpact/sim/decoder/vscode <br />
+    This directory contains files necessary to build syntax highlighting
+    extensions for VS Code for `.isa` and `.bin_fmt` files. Look in the
+    mpact/sim/decoder/vscode/README.md file for directions.
+
 *   mpact/sim/generic <br />
     This directory contains all the generic classes provided for use
     in writing MPACT-Sim instruction set simulators.