Make external typings re-usable across all the workspaces

Summary: Our external typings were only effective for the main "app" package. In this diff I've made them effective for all other workspaces too, and also cleaned up typescript configs.

Reviewed By: passy

Differential Revision: D21927361

fbshipit-source-id: ceb8009255583d969d79cc11b20dfe8b686f2fb3

desktop/tsconfig.base.json

@@ -1,11 +1,7 @@
 {
   "compilerOptions": {
     "module": "commonjs",
-    "lib": [
-      "es7",
-      "dom",
-      "es2017"
-    ],
+    "lib": ["es7", "dom", "es2017"],
     "esModuleInterop": true,
     "target": "ES2017",
     "removeComments": true,
@@ -16,5 +12,15 @@
     "moduleResolution": "node",
     "skipLibCheck": true,
     "strict": true,
+    "composite": true,
+    "incremental": true,
+    "baseUrl": ".",
+    "allowJs": true,
+    "rootDir": ".",
+    "paths": {
+      "flipper": ["./app/src"],
+      "flipper-*": ["./*/src"],
+      "*": ["./*", "./types/*"]
+    }
   }
 }