doc(#16): add pie

Author: peterpeterparker

doc/slides/deckdeckgo-slide-chart-layout.png renamed to doc/slides/deckdeckgo-slide-chart-line-layout.png

@@ -39,7 +39,8 @@ Some templates offer extra features as for example the slide [Code](#slide-code)
 
 * [Chart](#slide-chart)
 
-<img src="https://github.com/fluster/deckdeckgo/blob/master/doc/slides/deckdeckgo-slide-chart-layout.png" width="200px">
+<img src="https://github.com/fluster/deckdeckgo/blob/master/doc/slides/deckdeckgo-slide-chart-pie-layout.png" width="200px">
+<img src="https://github.com/fluster/deckdeckgo/blob/master/doc/slides/deckdeckgo-slide-chart-line-layout.png" width="200px">
 
 * [Youtube](#slide-youtube)
 
@@ -319,7 +320,8 @@ The "Chart" slide let you draw easily charts in your presentation.
 
 #### Layout
 
-<img src="https://github.com/fluster/deckdeckgo/blob/master/doc/slides/deckdeckgo-slide-chart-layout.png" width="450px">
+<img src="https://github.com/fluster/deckdeckgo/blob/master/doc/slides/deckdeckgo-slide-chart-pie-layout.png" width="450px">
+<img src="https://github.com/fluster/deckdeckgo/blob/master/doc/slides/deckdeckgo-slide-chart-line-layout.png" width="450px">
 
 #### Usage
 
@@ -350,7 +352,13 @@ The reasons behind are the following:
 
 #### Attributes
 
-This slide component offers the exact same attributes as the [DeckDeckGo] charts Web Component, see its [documentation](https://github.com/fluster/deckdeckgo-charts) for the details.
+This component offers the following options which could be set using attributes:
+
+| Attribute                      | Type   | Default   | Description   |
+| -------------------------- |:-----------------:|:-----------------:|:-----------------:|
+| type | string | pie | The type of the chart, `pie` or `line` |
+
+Furthermore, this slide component offers the same attributes as the [DeckDeckGo] charts Web Component, see its [documentation](https://github.com/fluster/deckdeckgo-charts) for the details.
 
 #### Theming