[docs] Mention in hompage hero that Core is free (mui#38075)

Signed-off-by: Matt <[email protected]>

Author: mbrookes

docs/src/components/home/Hero.tsx

@@ -98,9 +98,9 @@ export default function Hero() {
             with intuitive React UI tools
           </Typography>
           <Typography color="text.secondary" sx={{ mb: 3, maxWidth: 500 }}>
-            MUI offers a comprehensive suite of UI tools to help you ship new features faster. Start
-            with Material UI, our fully-loaded component library, or bring your own design system to
-            our production-ready components.
+            MUI offers a comprehensive suite of free UI tools to help you ship new features faster.
+            Start with Material UI, our fully-loaded component library, or bring your own design
+            system to our production-ready components.
           </Typography>
           <GetStartedButtons callToAction="Discover the Core libraries" to="/core/" />
         </Box>
@@ -109,7 +109,7 @@ export default function Hero() {
         p: 3,
         ml: 2,
         minWidth: 2000,
-        overflow: 'hidden', // the components on the Hero section are mostly illustrative, even though they're interactive. That's why scrolling is disabled.
+        overflow: 'hidden', // the components in the Hero section are mostly illustrative, even though they're interactive. That's why scrolling is disabled.
         '& > div': {
           width: 360,
           display: 'inline-flex',