Update contributing guide (#7202)

Author: Kartik Raj

CONTRIBUTING.md

@@ -37,7 +37,7 @@ npm ci
 python3 -m venv .venv
 # Activate the virtual environment as appropriate for your shell.
 npx gulp installPythonLibs
-# Optionally Update `launch.json` to set a value for the environment variable `CI_PYTHON_PATH` pointing to the fully qualified path of the above interpreter.
+# If your terminal doesn't recogonise the keyword `python3`, update `launch.json` to set a value for the environment variable `CI_PYTHON_PATH` pointing to the fully qualified path of the above interpreter.
 ```
 You may see warnings that ```The engine "vscode" appears to be invalid.```, you can ignore these.