Update wording

Author: Andrew Leach

README.md

@@ -90,7 +90,7 @@ const combobox = new Combobox(input, list, {tabInsertsSuggestions: true})
 These settings are available:
 
 - `tabInsertsSuggestions: boolean = true` - Control whether the highlighted suggestion is inserted when <kbd>Tab</kbd> is pressed (<kbd>Enter</kbd> will always insert a suggestion regardless of this setting). When `true`, tab-navigation will be hijacked when open (which can have negative impacts on accessibility) but the combobox will more closely imitate a native IDE experience.
-- `firstOptionSelectionMode: FirstOptionSelectionMode = 'none'` - This option dictates the default behaviour when no options have been selected yet and the user presses <kbd>Enter</kbd>. The following options of `FirstOptionSelectionMode` will do the following:
+- `firstOptionSelectionMode: FirstOptionSelectionMode = 'none'` - This option dictates the default behaviour when no options have been selected yet and the user presses <kbd>Enter</kbd>. The following values of `FirstOptionSelectionMode` will do the following:
    - `'none'`: Don't auto-select the first option at all.
    - `'active'`: Place the first option in an 'active' state where it is not selected (is not the `aria-activedescendant`) but will still be applied if the user presses `Enter`. To select the second item, the user would need to press the down arrow twice. This approach allows quick application of selections without disrupting screen reader users.
    > **Warning** Screen readers will not announce that the first item is the default. This should be announced explicitly with the use of `aria-live` status