update description and schema

Author: archmoj

src/traces/scattermapbox/attributes.js

@@ -37,7 +37,10 @@ module.exports = overrideAll({
             dflt: -1,
             min: -1,
             description: [
-                'Sets the steps for each cluster.'
+                'Sets how many points it takes to create a cluster or advance to the next cluster step.',
+                'Use this in conjunction with arrays for `size` and / or `color`.',
+                'If an integer, steps start at multiples of this number.',
+                'If an array, each step extends from the given value until one less than the next value.'
             ].join(' ')
         },
         size: {

test/plot-schema.json

@@ -53503,7 +53503,7 @@
      },
      "step": {
       "arrayOk": true,
-      "description": "Sets the steps for each cluster.",
+      "description": "Sets how many points it takes to create a cluster or advance to the next cluster step. Use this in conjunction with arrays for `size` and / or `color`. If an integer, steps start at multiples of this number. If an array, each step extends from the given value until one less than the next value.",
       "dflt": -1,
       "editType": "calc",
       "min": -1,