[docs][material-ui] Fix slider in color customization playground twitches when sliding (#43671)

Co-authored-by: nisarg-chudasama <[email protected]>

Author: Nashyn

docs/data/material/customization/color/ColorTool.js

@@ -237,7 +237,7 @@ function ColorTool() {
             onChange={handleChangeShade(intent)}
             aria-labelledby={`${intent}ShadeSliderLabel`}
           />
-          <Typography>{shades[intentShade]}</Typography>
+          <Typography minWidth={40}>{shades[intentShade]}</Typography>
         </Box>
         <Box sx={{ width: 192 }}>
           {hues.map((hue) => {