doc(wasm): Add README for Go/wasm stuff

Author: pdubroy

packages/wasm/test/go/README.md

@@ -0,0 +1,67 @@
+# Ohm-WASM Go Integration
+
+This directory contains a Go implementation for running Ohm grammars compiled to WebAssembly. It provides a simple API to load grammar modules, match input against them, and access the resulting concrete syntax trees.
+
+## Overview
+
+The implementation consists of two main components:
+
+1. **matcher.go**: A Go implementation of the JavaScript `WasmMatcher` class from the Ohm `wasm` package
+2. **testmain.go**: A command-line program that demonstrates how to use the WasmMatcher
+
+## WasmMatcher
+
+The `WasmMatcher` class provides a high-level API for working with Ohm grammars compiled to WebAssembly:
+
+```go
+// Create a new matcher
+matcher := NewWasmMatcher(ctx)
+
+// Load a grammar module
+err := matcher.LoadModule("path/to/grammar.wasm")
+
+// Set input text
+matcher.SetInput("text to match")
+
+// Match against the grammar
+success, err := matcher.Match()
+
+// Match against a specific rule
+success, err := matcher.MatchRule("specificRule")
+
+// Access the concrete syntax tree
+cstRoot, err := matcher.GetCstRoot()
+```
+
+## Command-Line Usage
+
+You can use the command-line program to test Ohm grammars:
+
+```
+# Test the simple add function (automatically detected)
+./testmain -wasm ../data/_add.wasm
+
+# Match input against a grammar
+./testmain -wasm path/to/grammar.wasm -input "text to match"
+
+# Specify a start rule
+./testmain -wasm path/to/grammar.wasm -input "text to match" -rule "StartRule"
+```
+
+### Example with ES5 Grammar
+
+```
+./testmain -wasm ../data/_es5.wasm -input "var x = 3;"
+```
+
+## Build Instructions
+
+Use the Makefile in the parent directory to build and test:
+
+```
+# Build the testmain program
+make test/go/testmain
+
+# Run the test with the ES5 grammar
+make go-test-es5
+```