chore: typo (#2423)

Author: tolu

docs/config/index.md

@@ -240,7 +240,7 @@ export default ({ command, mode }) => {
 - **Type:** `boolean`
 - **Default:** `false`
 
-  If set to `true`, imported JSON will be transformed into `export default JSON.parse("...")` which is significantly more performant than Object literals, espeically when the JSON file is large.
+  If set to `true`, imported JSON will be transformed into `export default JSON.parse("...")` which is significantly more performant than Object literals, especially when the JSON file is large.
 
   Enabling this disables named imports.