Documentation improvement suggestion: clarify that this *parses* and replaces contents of import.meta.env, not only validates

[fnimick]

It's not clear (at least to me) from the README that this plugin actually replaces the contents of import.meta.env with the parsed output. I was expecting the output to still be e.g. strings for Schema.boolean rather than the coerced boolean value, and that I would still have to do that coercion myself.