doc: add GitHub star history

Add the GitHub star history to illustrate the project's popularity and
enhance its chances of wider adoption.

Reference:

- trueNAHO/dotfiles@44fbb60

README.md

@@ -53,3 +53,21 @@ or ask on [GitHub Discussions](https://github.com/danth/stylix/discussions).
 | Environment | Wallpaper                                                                               | Colour scheme       | Fonts                | Full configuration                                  |
 |-------------|-----------------------------------------------------------------------------------------|---------------------|----------------------|-----------------------------------------------------|
 | Hyprland    | Taken from [raison d'etre by Eve](https://www.youtube.com/watch?v=ulfY8WQE_HE)          | Generated by Stylix | DeJavu               | [See here](https://github.com/SomeGuyNamedMy/users) |
+
+<picture>
+  <source
+    media="(prefers-color-scheme: dark)"
+    srcset="https://api.star-history.com/svg?repos=danth/stylix&amp;type=Date&amp;theme=dark"
+  />
+
+  <source
+    media="(prefers-color-scheme: light)"
+    srcset="https://api.star-history.com/svg?repos=danth/stylix&amp;type=Date"
+  />
+
+  <img
+    alt="Star History Chart"
+    src="https://api.star-history.com/svg?repos=danth/stylix&amp;type=Date&amp;theme=dark"
+    width="100%"
+  />
+</picture>