Set indentation min to -(min itemwidth / 2)

Author: my-tien

src/components/legend/attributes.js

@@ -107,7 +107,7 @@ module.exports = {
     },
     indentation: {
         valType: 'number',
-        min: 0,
+        min: -15,
         dflt: 0,
         editType: 'legend',
         description: 'Sets the indentation (in px) of the legend entries.',

test/plot-schema.json

@@ -2852,7 +2852,7 @@
      "description": "Sets the indentation (in px) of the legend entries.",
      "dflt": 0,
      "editType": "legend",
-     "min": 0,
+     "min": -15,
      "valType": "number"
     },
     "itemclick": {