feat(typescript): Add basic typescript definitions

Adds basic type definitions

- Fixes apertureless#376

package.json

@@ -40,10 +40,12 @@
   "unpkg": "dist/vue-chartjs.min.js",
   "module": "es/index.js",
   "jsnext:main": "es/index.js",
+  "typings": "types/index.d.ts",
   "files": [
     "src",
     "dist",
-    "es"
+    "es",
+    "types/*.d.ts"
   ],
   "scripts": {
     "dev": "node build/dev-server.js",

types/components.d.ts

@@ -0,0 +1,7 @@
+import Vue from 'vue'
+
+/** vue-chartjs component common definition */
+export declare class BaseChart extends Vue {
+  addPlugin (plugin?: string[]): void
+  renderChart (chartData: any, options?: any): void
+}

types/index.d.ts

@@ -0,0 +1,19 @@
+import { BaseChart } from './components'
+
+declare module 'vue-chartjs' {
+  export function generateChart(chartId: string, chartType: string): any;
+  export class Bar extends BaseChart {}
+  export class HorizontalBar extends BaseChart {}
+  export class Doughnut extends BaseChart {}
+  export class Line extends BaseChart {}
+  export class Pie extends BaseChart {}
+  export class PolarArea extends BaseChart {}
+  export class Radar extends BaseChart {}
+  export class Bubble extends BaseChart {}
+  export class Scatter extends BaseChart {}
+  export const mixins: {
+    reactiveData: any
+    reactiveProp: any
+  }
+}
+