chore: add devcontainer support

.devcontainer/devcontainer.json

@@ -0,0 +1,33 @@
+{
+  "name": "OpenFeature .NET SDK",
+  "image": "mcr.microsoft.com/devcontainers/dotnet:9.0-bookworm",
+  "features": {
+    "ghcr.io/devcontainers/features/dotnet:latest": {
+      "version": "9.0",
+      "additionalVersions": "8.0"
+    },
+    "ghcr.io/devcontainers/features/github-cli:latest": {},
+    "ghcr.io/devcontainers/features/docker-in-docker": {}
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "EditorConfig.EditorConfig",
+        "GitHub.copilot",
+        "GitHub.copilot-chat",
+        "GitHub.vscode-github-actions",
+        "GitHub.vscode-pull-request-github",
+        "ms-dotnettools.csharp",
+        "esbenp.prettier-vscode",
+        "redhat.vscode-yaml",
+        "cucumberopen.cucumber-official",
+        "ms-dotnettools.csdevkit"
+      ]
+    }
+  },
+  "remoteUser": "vscode",
+  "hostRequirements": {
+    "memory": "8gb"
+  },
+  "postCreateCommand": "git submodule update --init --recursive"
+}

.gitignore

@@ -8,7 +8,6 @@
 *.user
 *.userosscache
 *.sln.docstates
-.devcontainer/
 
 # User-specific files (MonoDevelop/Xamarin Studio)
 *.userprefs

CONTRIBUTING.md

@@ -18,6 +18,26 @@ On all platforms, the minimum requirements are:
 -   JetBrains Rider 2022.2+ or Visual Studio 2022+ or Visual Studio Code
 -   .NET Framework 4.6.2+
 
+### Development Containers
+
+This repository includes support for [Development Containers](https://containers.dev/) (devcontainers), which provide a consistent, containerized development environment. The devcontainer configuration includes all necessary dependencies and tools pre-configured.
+
+To use the devcontainer:
+
+1. **Prerequisites**: Install [Docker](https://www.docker.com/) and either:
+   -   [Visual Studio Code](https://code.visualstudio.com/) with the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers)
+   -   [GitHub Codespaces](https://github.com/features/codespaces)
+
+2. **Using with VS Code**:
+   -   Open the repository in VS Code
+   -   When prompted, click "Reopen in Container" or use the Command Palette (`Ctrl+Shift+P` / `Cmd+Shift+P`) and select "Dev Containers: Reopen in Container"
+
+3. **Using with GitHub Codespaces**:
+   -   Navigate to the repository on GitHub
+   -   Click the "Code" button and select "Create codespace on [branch-name]"
+
+The devcontainer provides a pre-configured environment with the .NET SDK and all necessary tools for development and testing.
+
 ## Pull Request
 
 All contributions to the OpenFeature project are welcome via GitHub pull requests.