chore: Using .tsx config theme

Author: LuchoTurtle

next.config.js

@@ -1,6 +1,6 @@
 const withNextra = require("nextra")({
   theme: "./theme/src/index.tsx",
-  themeConfig: "./theme.config.jsx",
+  themeConfig: "./theme.config.tsx",
   defaultShowCopyCode: true
 });