add theme augment to docs

Author: siriwatknp

docs/types/theme-augment.d.ts

@@ -0,0 +1,6 @@
+import type { Theme } from '@mui/material/styles';
+import type { Components } from '@mui/material/stylesDeprecated';
+
+declare module '@mui/material/styles' {
+  interface ThemeComponents extends Components<Theme> {}
+}