Fix links to images in translated documents

Author: k-rumi

docs/de/README.md

@@ -262,30 +262,30 @@ Sometimes you need more control over chart.js. Thats why you can access the char
   There are two versions of the Bar chart. `{Bar}` and `{HorizontalBar}`
 </p>
 
-![Bar](assets/bar.png)
+![Bar](../assets/bar.png)
 ### Line Chart
 
-![Line](assets/line.png)
+![Line](../assets/line.png)
 
 ### Doughnut
 
-![Doughnut](assets/doughnut.png)
+![Doughnut](../assets/doughnut.png)
 
 ### Pie
 
-![Pie](assets/pie.png)
+![Pie](../assets/pie.png)
 
 ### Radar
 
-![Pie](assets/radar.png)
+![Pie](../assets/radar.png)
 
 ### Polar Area
 
-![Pie](assets/polar.png)
+![Pie](../assets/polar.png)
 
 ### Bubble
 
-![Bubble](assets/bubble.png)
+![Bubble](../assets/bubble.png)
 
 ## Webpack, Browserify and dist files.
 

docs/ja/README.md

@@ -264,30 +264,30 @@ export default Line.extend({
   棒グラフには `{Bar}` と `{HorizontalBar}` の2つのバージョンがあります。
 </p>
 
-![Bar](assets/bar.png)
+![Bar](../assets/bar.png)
 ### 折れ線グラフ
 
-![Line](assets/line.png)
+![Line](../assets/line.png)
 
 ### ドーナツチャート
 
-![Doughnut](assets/doughnut.png)
+![Doughnut](../assets/doughnut.png)
 
 ### パイチャート
 
-![Pie](assets/pie.png)
+![Pie](../assets/pie.png)
 
 ### レーダーチャート
 
-![Pie](assets/radar.png)
+![Pie](../assets/radar.png)
 
 ### 鶏頭図
 
-![Pie](assets/polar.png)
+![Pie](../assets/polar.png)
 
 ### バブルチャート
 
-![Bubble](assets/bubble.png)
+![Bubble](../assets/bubble.png)
 
 
 ## ビルド方法の違い

docs/pt-br/README.md

@@ -221,31 +221,31 @@ export default Line.extend({
 
 ### Gráfico de Barra
 
-![Barra](assets/bar.png)
+![Barra](../assets/bar.png)
 
 ### Gráfico de Linha
 
-![Linha](assets/line.png)
+![Linha](../assets/line.png)
 
 ### Donut
 
-![Donut](assets/doughnut.png)
+![Donut](../assets/doughnut.png)
 
 ### Pizza
 
-![Pizza](assets/pie.png)
+![Pizza](../assets/pie.png)
 
 ### Radar
 
-![Radar](assets/radar.png)
+![Radar](../assets/radar.png)
 
 ### Área Polar
 
-![Área Polar](assets/polar.png)
+![Área Polar](../assets/polar.png)
 
 ### Bolha
 
-![Bolha](assets/bubble.png)
+![Bolha](../assets/bubble.png)
 
 ## Configurações de Build