add csharp examples (#10)

03_recursion/csharp/02_greet/.vscode/launch.json

@@ -0,0 +1,23 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": ".NET Core Launch (console)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            "program": "${workspaceRoot}/bin/Debug/netcoreapp1.0/02_greet.dll",
+            "args": [],
+            "cwd": "${workspaceRoot}",
+            "externalConsole": false,
+            "stopAtEntry": false,
+            "internalConsoleOptions": "openOnSessionStart"
+        },
+        {
+            "name": ".NET Core Attach",
+            "type": "coreclr",
+            "request": "attach",
+            "processId": "${command.pickProcess}"
+        }
+    ]
+}

03_recursion/csharp/02_greet/.vscode/tasks.json

@@ -0,0 +1,16 @@
+{
+    "version": "0.1.0",
+    "command": "dotnet",
+    "isShellCommand": true,
+    "args": [],
+    "tasks": [
+        {
+            "taskName": "build",
+            "args": [
+                "${workspaceRoot}/project.json"
+            ],
+            "isBuildCommand": true,
+            "problemMatcher": "$msCompile"
+        }
+    ]
+}