[Side Sheet][Docs] Add links to class definitions in Side Sheet docum…

…entation and revise version guidance.

Now that 1.8.0 has reached stable, class definitions are available and version guidance doesn't need to point to an alpha release.

PiperOrigin-RevId: 532897620

docs/components/SideSheet.md

@@ -31,8 +31,8 @@ Material Components for Android library. For more information, go to the
 [Getting started](https://github.com/material-components/material-components-android/tree/master/docs/getting-started.md)
 page.
 
-Note: Side sheets are available starting from `1.8.0-alpha02`. To use side sheets,
-make sure you're depending on [library version `1.8.0-alpha02`](https://github.com/material-components/material-components-android/releases/tag/1.8.0-alpha02)
+Note: Side sheets were introduced in `1.8.0`. To use side sheets, make sure
+you're depending on [library version `1.8.0`](https://github.com/material-components/material-components-android/releases/tag/1.8.0)
 or later.
 
 Standard side sheet basic usage:
@@ -346,6 +346,8 @@ theme.
 API and source code:
 
 *   `SideSheetBehavior`
+    *   [Class definition](https://developer.android.com/reference/com/google/android/material/sidesheet/SideSheetBehavior)
     *   [Class source](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/sidesheet/SideSheetBehavior.java)
 *   `SideSheetDialog`
+    *   [Class definition](https://developer.android.com/reference/com/google/android/material/sidesheet/SideSheetDialog)
     *   [Class source](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/sidesheet/SideSheetDialog.java)