restructure README (#38)

d3/d3#3775

README.md

@@ -1,52 +1,12 @@
 # d3-polygon
 
-This module provides a few basic geometric operations for two-dimensional polygons. Each polygon is represented as an array of two-element arrays [​[<i>x1</i>, <i>y1</i>], [<i>x2</i>, <i>y2</i>], …], and may either be closed (wherein the first and last point are the same) or open (wherein they are not). Typically polygons are in counterclockwise order, assuming a coordinate system where the origin ⟨0,0⟩ is in the top-left corner.
+<a href="https://d3js.org"><img src="https://github.com/d3/d3/raw/main/docs/public/logo.svg" width="256" height="256"></a>
 
-## Installing
+This module provides a few basic geometric operations for two-dimensional polygons.
 
-If you use npm, `npm install d3-polygon`. You can also download the [latest release on GitHub](https://github.com/d3/d3-polygon/releases/latest). For vanilla HTML in modern browsers, import d3-polygon from Skypack:
+## Resources
 
-```html
-<script type="module">
-
-import {polygonHull} from "https://cdn.skypack.dev/d3-polygon@3";
-
-const hull = polygonHull(points);
-
-</script>
-```
-
-For legacy environments, you can load d3-polygon’s UMD bundle from an npm-based CDN such as jsDelivr; a `d3` global is exported:
-
-```html
-<script src="https://cdn.jsdelivr.net/npm/d3-polygon@3"></script>
-<script>
-
-const hull = d3.polygonHull(points);
-
-</script>
-```
-
-## API Reference
-
-<a href="#polygonArea" name="polygonArea">#</a> d3.<b>polygonArea</b>(<i>polygon</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/area.js "Source Code")
-
-Returns the signed area of the specified *polygon*. If the vertices of the polygon are in counterclockwise order (assuming a coordinate system where the origin ⟨0,0⟩ is in the top-left corner), the returned area is positive; otherwise it is negative, or zero.
-
-<a href="#polygonCentroid" name="polygonCentroid">#</a> d3.<b>polygonCentroid</b>(<i>polygon</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/centroid.js "Source Code")
-
-Returns the [centroid](https://en.wikipedia.org/wiki/Centroid) of the specified *polygon*.
-
-<a href="#polygonHull" name="polygonHull">#</a> d3.<b>polygonHull</b>(<i>points</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/hull.js#L23 "Source Code")
-
-<a href="http://bl.ocks.org/mbostock/6f14f7b7f267a85f7cdc"><img src="https://raw.githubusercontent.com/d3/d3-polygon/master/img/hull.png" width="250" height="250"></a>
-
-Returns the [convex hull](https://en.wikipedia.org/wiki/Convex_hull) of the specified *points* using [Andrew’s monotone chain algorithm](http://en.wikibooks.org/wiki/Algorithm_Implementation/Geometry/Convex_hull/Monotone_chain). The returned hull is represented as an array containing a subset of the input *points* arranged in counterclockwise order. Returns null if *points* has fewer than three elements.
-
-<a href="#polygonContains" name="polygonContains">#</a> d3.<b>polygonContains</b>(<i>polygon</i>, <i>point</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/contains.js "Source Code")
-
-Returns true if and only if the specified *point* is inside the specified *polygon*.
-
-<a href="#polygonLength" name="polygonLength">#</a> d3.<b>polygonLength</b>(<i>polygon</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/length.js "Source Code")
-
-Returns the length of the perimeter of the specified *polygon*.
+- [Documentation](https://d3js.org/d3-polygon)
+- [Examples](https://observablehq.com/collection/@d3/d3-polygon)
+- [Releases](https://github.com/d3/d3-polygon/releases)
+- [Getting help](https://d3js.org/community)