Update .Net version to .Net 7 and add some extensions

.devcontainer/Dockerfile

@@ -3,7 +3,7 @@
 # Licensed under the MIT License. See https://go.microsoft.com/fwlink/?linkid=2090316 for license information.
 #-------------------------------------------------------------------------------------------------------------
 
-FROM mcr.microsoft.com/dotnet/sdk:5.0-focal
+FROM mcr.microsoft.com/dotnet/sdk:7.0
 
 # Avoid warnings by switching to noninteractive
 ENV DEBIAN_FRONTEND=noninteractive

.devcontainer/devcontainer.json

@@ -1,5 +1,5 @@
 {
-	"name": "F# (.NET 5.0)",
+	"name": "F# (.NET 7.0)",
 	"dockerFile": "Dockerfile",
 
 	// Set *default* container specific settings.json values on container create.
@@ -12,7 +12,12 @@
 	// Add the IDs of extensions you want installed when the container is created.
 	"extensions": [
 		"Ionide.Ionide-fsharp",
-		"muhammad-sammy.csharp"
+		"muhammad-sammy.csharp",
+		"formulahendry.code-runner",
+		"GitHub.copilot",
+		"ms-dotnettools.dotnet-interactive-vscode",
+		"zhuangtongfa.material-theme",
+		"PKief.material-icon-theme"
 	],
 
 	// Use 'forwardPorts' to make a list of ports inside the container available locally.

Playgroud.dib

@@ -0,0 +1,7 @@
+#!meta
+
+{"kernelInfo":{"defaultKernelName":"fsharp","items":[{"aliases":[],"name":"fsharp"}]}}
+
+#!fsharp
+
+printfn "Hello World from F#!"

playground.fsproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net7.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>