fix: spelling (#695)

Author: rvedotrc

src/pages/components/combobox.mdx

@@ -153,7 +153,7 @@ import NestedCode from '!!raw-loader!../../examples/combobox/Nested.tsx';
 
 ### Nested multiselect
 
-A multiselect requires additional consideration for seleting options at nested levels.
+A multiselect requires additional consideration for selecting options at nested levels.
 
 import NestedMultiselect from '../../examples/combobox/NestedMultiselect.tsx';
 import NestedMultiselectCode from '!!raw-loader!../../examples/combobox/NestedMultiselect.tsx';