accommodate Vite tomfoolery

[JThompson-VI]

First off thank you for maintaining such a great project, and I 100% understand if you don't want this change.

During the building of a Vite project it replaces instances of the code 'process.env.NODE_ENV' with the literal '"production"' this causes a syntax error in the isDev function in lib/utils/index.js as it calls global.process.env.NODE_ENV. If this code were changed to global.process.env['NODE_ENV'] it would work with vite.

diff --git a/lib/utils/index.js b/lib/utils/index.js
index 832dde65..116874e6 100644
--- a/lib/utils/index.js
+++ b/lib/utils/index.js
@@ -31,7 +31,7 @@ function isText(txt) {
 // Proper configuration is having NODE_ENV = 'development', but this
 // method only checks for 'dev' being present, and regardless of the case.
 function isDev() {
-    const env = global.process.env.NODE_ENV || '';
+    const env = global.process.env[`NODE_ENV`] || '';
     return env.toLowerCase().indexOf('dev') !== -1;
 }