docs: clarify model validation execution steps

website/versioned_docs/version-0.21/model-api.md

@@ -15,6 +15,18 @@ Below are examples of API use.
 
 ## Validating JSON data using a Model
 
+To run the validation code below, you will need a Node.js environment.
+
+**Step-by-step setup:**
+1. Ensure you have [Node.js](https://nodejs.org/) installed.
+2. Create a new folder, open it in a code editor like [VS Code](https://code.visualstudio.com/), and open a new terminal.
+3. Initialize a new Node.js project and install the Concerto core component:
+   ```bash
+   npm init -y
+   npm install @accordproject/concerto-core
+   ```
+4. Create a new file named `validate.js` and paste the following code into it:
+
 ```js
 const ModelManager = require('@accordproject/concerto-core').ModelManager;
 const Concerto = require('@accordproject/concerto-core').Concerto;
@@ -37,6 +49,12 @@ const concerto = new Concerto(modelManager);
 concerto.validate(postalAddress);
 ```
 
+5. Run the script from the terminal:
+   ```bash
+   node validate.js
+   ```
+   *If everything is correct, nothing will be printed to the console, meaning validation succeeded.*
+
 Now try validating this instance:
 
 ```

website/versioned_docs/version-0.30.0/model-api.md

@@ -15,6 +15,18 @@ Below are examples of API use.
 
 ## Validating JSON data using a Model
 
+To run the validation code below, you will need a Node.js environment.
+
+**Step-by-step setup:**
+1. Ensure you have [Node.js](https://nodejs.org/) installed.
+2. Create a new folder, open it in a code editor like [VS Code](https://code.visualstudio.com/), and open a new terminal.
+3. Initialize a new Node.js project and install the Concerto core component:
+   ```bash
+   npm init -y
+   npm install @accordproject/concerto-core
+   ```
+4. Create a new file named `validate.js` and paste the following code into it:
+
 ```js
 const ModelManager = require('@accordproject/concerto-core').ModelManager;
 const Concerto = require('@accordproject/concerto-core').Concerto;
@@ -37,6 +49,12 @@ const concerto = new Concerto(modelManager);
 concerto.validate(postalAddress);
 ```
 
+5. Run the script from the terminal:
+   ```bash
+   node validate.js
+   ```
+   *If everything is correct, nothing will be printed to the console, meaning validation succeeded.*
+
 Now try validating this instance:
 
 ```