Add option for incremental build

Author: PKief

.gitignore

@@ -1,2 +1,3 @@
 node_modules
-out
+out
+*.tsbuildinfo

package.json

@@ -2,7 +2,7 @@
   "name": "vscode-typescript-debugging",
   "version": "1.0.0",
   "devDependencies": {
-    "typescript": "^2.7.2"
+    "typescript": "^3.4.1"
   },
   "scripts": {
     "start": "node out/app.js",

tsconfig.json

@@ -3,6 +3,7 @@
         "outDir": "./out",
         "rootDir": "./src",
         "sourceMap": true,
+        "incremental": true,
         "moduleResolution": "node",
         "target": "es5"
     }