links to d3@6 versions

Author: Fil

README.md

@@ -24,11 +24,11 @@ If you use NPM, `npm install d3-scale`. Otherwise, download the [latest release]
 
 ```html
 <script src="https://d3js.org/d3-array.v2.min.js"></script>
-<script src="https://d3js.org/d3-color.v1.min.js"></script>
-<script src="https://d3js.org/d3-format.v1.min.js"></script>
-<script src="https://d3js.org/d3-interpolate.v1.min.js"></script>
-<script src="https://d3js.org/d3-time.v1.min.js"></script>
-<script src="https://d3js.org/d3-time-format.v2.min.js"></script>
+<script src="https://d3js.org/d3-color.v2.min.js"></script>
+<script src="https://d3js.org/d3-format.v2.min.js"></script>
+<script src="https://d3js.org/d3-interpolate.v2.min.js"></script>
+<script src="https://d3js.org/d3-time.v2.min.js"></script>
+<script src="https://d3js.org/d3-time-format.v3.min.js"></script>
 <script src="https://d3js.org/d3-scale.v3.min.js"></script>
 <script>