Update the version number.

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@splidejs/splide",
-  "version": "3.1.9",
+  "version": "3.2.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@splidejs/splide",
-  "version": "3.1.9",
+  "version": "3.2.0",
   "description": "Splide is a lightweight, flexible and accessible slider/carousel. No dependencies, no Lighthouse errors.",
   "author": "Naotoshi Fujita",
   "license": "MIT",