Update README.md for clarity and template availability (#58)

Author: shibayan

README.md

@@ -1,18 +1,30 @@
-# Dev Container templates
+# Dev Container Templates
 
-The repository has a customized Dev Container template.
+A collection of [Dev Container Templates](https://containers.dev/implementors/templates/) for Azure Functions development. Each template provides a ready-to-use, multi-container environment with language-specific tooling and an [Azurite](https://github.com/Azure/Azurite) storage emulator.
 
-## Azure Functions templates
+## Available Templates
 
-The Dev Container Template for Azure Functions includes two containers, one for each language and an Azurite container.
+| Template | Languages / Runtimes | Supported Versions |
+| --- | --- | --- |
+| [Azure Functions (.NET)](./src/azure-functions-dotnet) | C#, .NET | 8.0 / 9.0 / 10.0 |
+| [Azure Functions (Java)](./src/azure-functions-java) | Java | 8 / 11 / 17 / 21 / 25 |
+| [Azure Functions (Node.js)](./src/azure-functions-node) | JavaScript, TypeScript | 20 / 22 / 24 |
+| [Azure Functions (PowerShell)](./src/azure-functions-powershell) | PowerShell | 7.4 |
+| [Azure Functions (Python)](./src/azure-functions-python) | Python | 3.10 / 3.11 / 3.12 / 3.13 / 3.14 |
 
-| Template                                                                   | Description                                                   |
-| -------------------------------------------------------------------------- | ------------------------------------------------------------- |
-| [Azure Functions (.NET)](./src/azure-functions-dotnet/README.md)           | Develop Azure Functions using .NET 8/9/10                     |
-| [Azure Functions (Java)](./src/azure-functions-java/README.md)             | Develop Azure Functions using Java 8/11/17/21                 |
-| [Azure Functions (Node.js)](./src/azure-functions-node/README.md)          | Develop Azure Functions using Node.js 20/22/24                |
-| [Azure Functions (PowerShell)](./src/azure-functions-powershell/README.md) | Develop Azure Functions using PowerShell 7.4                  |
-| [Azure Functions (Python)](./src/azure-functions-python/README.md)         | Develop Azure Functions using Python 3.10/3.11/3.12/3.13/3.14 |
+> All templates include the Azure Functions Core Tools (version selectable, default: `latest`).
+
+## Usage
+
+1. Open the Command Palette in VS Code and select **Dev Containers: Add Dev Container Configuration Files...**
+2. Choose **Show All Definitions...**, then search for `Azure Functions`
+3. Select the template that matches your language and configure the version options
+
+Alternatively, you can use the [Dev Container CLI](https://github.com/devcontainers/cli):
+
+```sh
+devcontainer templates apply -t ghcr.io/shibayan/devcontainers/azure-functions-node
+```
 
 ## License