Update index.md (#27434)

Added hyperlinks to examples and helpful utility section callouts. This will take people right to the definitive source if they want to learn more.

guide/english/d3/index.md

@@ -16,33 +16,33 @@ title: D3
 *D3** does not introduce a new visual representation. Unlike **Processing**, **Raphaël**, or **Protovis**, *D3's* vocabulary of graphical marks comes directly from web standards: HTML, SVG, and CSS - https://d3js.org/
 
 ###### Get Started
-There are over 20,000+ **D3.js** examples you could learn from, but you never know how approachable any given one will be! So, the question is - how do you build up your visualization from first principles? As you've probably seen, D3's API is massive, so lets call out a few of the utilities that will be particularly helpful early on:
+There are over [20,000+ **D3.js** examples](https://github.com/d3/d3/wiki/Gallery) you could learn from, but you never know how approachable any given one will be! So, the question is - how do you build up your visualization from first principles? As you've probably seen, D3's API is massive, so lets call out a few of the utilities that will be particularly helpful early on:
 
-- **d3-scale**
+- **[d3-scale](https://github.com/d3/d3-scale)**
 
 ![](https://i0.wp.com/pbiswas101.files.wordpress.com/2018/07/scale.png?w=400&h=100)
 
-- **d3-shape**
+- **[d3-shape](https://github.com/d3/d3-shape)**
 
 ![](https://i0.wp.com/pbiswas101.files.wordpress.com/2018/07/shape.png?w=400&h=100)
 
-- **d3-selection**
+- **[d3-selection](https://github.com/d3/d3-selection)**
 
 ![](https://i0.wp.com/pbiswas101.files.wordpress.com/2018/07/selection.gif?w=400&h=100)
 
-- **d3-collection**
+- **[d3-collection](https://github.com/d3/d3-collection)**
 
 ![](https://i0.wp.com/pbiswas101.files.wordpress.com/2018/07/collection.png?w=400&h=100)
 
-- **d3-hierarchy**
+- **[d3-hierarchy](https://github.com/d3/d3-hierarchy)**
 
 ![](https://i2.wp.com/pbiswas101.files.wordpress.com/2018/07/hierarchy.png?w=400&h=100)
 
-- **d3-zoom**
+- **[d3-zoom](https://github.com/d3/d3-zoom)**
 
 ![](https://i1.wp.com/pbiswas101.files.wordpress.com/2018/07/zoom.gif?w=400&h=100)
 
-- **d3-force**
+- **[d3-force](https://github.com/d3/d3-force)**
 
 ![](https://i1.wp.com/pbiswas101.files.wordpress.com/2018/07/force.gif?w=400&h=100)
 
@@ -54,9 +54,7 @@ There are over 20,000+ **D3.js** examples you could learn from, but you never kn
  ### Resources
 
 - [Wikipedia](https://en.wikipedia.org/wiki/D3.js)
-- [Wikipedia](https://en.wikipedia.org/wiki/Document_Object_Model)
 - [Blockbuilder](http://blockbuilder.org/search)
 - [D3 in Depth](https://d3indepth.com)
 - [Learning D3](https://davidwalsh.name/learning-d3)
 - [Motion Visualization with D3](https://omid.al/posts/2016-08-23-MocapVis-D3.html)
- ------------