chore: re-add mui.d.ts

Otherwise,  error TS2339: Property 'border' does not exist on type 'Palette' is shown

Author: timurbazhirov

src/theme/mui.d.ts

@@ -0,0 +1,25 @@
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+import { Palette, PaletteColor, Theme } from "@mui/material/styles";
+
+declare module "@mui/material/styles" {
+    interface Theme {
+        iconDefaultFontSize: number;
+    }
+
+    interface Palette {
+        border: PaletteColor;
+        neutral: PaletteColor;
+    }
+}
+
+declare module "@mui/material/Button" {
+    interface ButtonPropsColorOverrides {
+        neutral: true;
+    }
+}
+
+declare module "@mui/material/IconButton" {
+    interface IconButtonPropsColorOverrides {
+        neutral: true;
+    }
+}