docs: Add documentation for running Rhai tests

- Added a comprehensive guide on running Rhai tests within the
  SAL library.  This includes instructions for running all tests,
  tests for specific modules, and individual tests.
- Created a shell script (`run_rhai_tests.sh`) to simplify running
  all Rhai tests and provide a summary of results.  This improves
  the testing workflow and makes it easier to identify failures.

docs/rhai/running_tests.md

@@ -0,0 +1,76 @@
+# Running Rhai Tests
+
+This document describes how to run the Rhai tests for the SAL library.
+
+## Test Structure
+
+The Rhai tests are organized by module in the `src/rhai_tests` directory:
+
+- `src/rhai_tests/os/`: Tests for the OS module
+- `src/rhai_tests/git/`: Tests for the Git module
+
+Each module directory contains:
+- Individual test scripts (e.g., `01_file_operations.rhai`)
+- A test runner script (`run_all_tests.rhai`) that runs all tests for that module
+
+## Running Tests
+
+### Running All Tests
+
+To run all Rhai tests across all modules, use the provided shell script:
+
+```bash
+./run_rhai_tests.sh
+```
+
+This script:
+1. Finds all test runner scripts in the `src/rhai_tests` directory
+2. Runs each test runner
+3. Reports the results for each module
+4. Provides a summary of all test results
+
+The script will exit with code 0 if all tests pass, or code 1 if any tests fail.
+
+### Running Tests for a Specific Module
+
+To run tests for a specific module, use the `herodo` command with the module's test runner:
+
+```bash
+herodo --path src/rhai_tests/os/run_all_tests.rhai
+```
+
+### Running Individual Tests
+
+To run a specific test, use the `herodo` command with the test script:
+
+```bash
+herodo --path src/rhai_tests/os/01_file_operations.rhai
+```
+
+## Test Output
+
+The test output includes:
+- Information about what's being tested
+- Success or failure messages for each test
+- A summary of test results
+
+Successful tests are indicated with a checkmark (✓), while failed tests show an error message.
+
+## Adding New Tests
+
+When adding new tests:
+
+1. Create a new test script in the appropriate module directory
+2. Update the module's test runner script to include the new test
+3. Update the module's documentation to describe the new test
+
+The `run_rhai_tests.sh` script will automatically find and run the new tests as long as they're included in a module's test runner script.
+
+## Troubleshooting
+
+If tests fail, check the following:
+
+1. Make sure the `herodo` binary is in your PATH
+2. Verify that the test scripts have the correct permissions
+3. Check for any dependencies required by the tests (e.g., `git` for Git module tests)
+4. Look for specific error messages in the test output