chore: create tsconfig.build.json for building

to avoid palantir/tslint#3677

Author: runjuu

package.json

@@ -7,7 +7,7 @@
   "scripts": {
     "dev": "parcel ./demo/index.html",
     "build:demo": "parcel build ./demo/index.html --out-dir ./demo/dist --public-url ./",
-    "build": "rm -rf ./dist && tsc",
+    "build": "rm -rf ./dist && tsc -p ./tsconfig.build.json",
     "prettier": "prettier '@(src|demo)/**/*.@(ts|tsx|html|less)' --write",
     "lint": "tslint -p tsconfig.json --fix",
     "test": "echo \"Error: no test specified\" && exit 1"

tsconfig.build.json

@@ -0,0 +1,4 @@
+{
+  "extends": "./tsconfig.json",
+  "include": ["src"]
+}

tsconfig.json

@@ -16,5 +16,5 @@
     "jsx": "react",
     "target": "es5"
   },
-  "include": ["src"]
+  "include": ["src", "demo"]
 }