Add: Categories chips & bar

src/main/res/layout/fragment_explore_x.xml

@@ -15,7 +15,8 @@
  ~ You should have received a copy of the GNU Affero General Public License
  ~ along with this program.  If not, see <https://www.gnu.org/licenses/>.
  -->
-<layout xmlns:android="http://schemas.android.com/apk/res/android">
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
 
     <data>
 
@@ -31,6 +32,21 @@
             android:nestedScrollingEnabled="true"
             android:orientation="vertical">
 
+            <HorizontalScrollView
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:scrollbars="none">
+
+                <com.google.android.material.chip.ChipGroup
+                    android:id="@+id/categories"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:nestedScrollingEnabled="true"
+                    android:paddingHorizontal="@dimen/shape_margin_medium"
+                    app:selectionRequired="true"
+                    app:singleSelection="true" />
+            </HorizontalScrollView>
+
             <androidx.compose.ui.platform.ComposeView
                 android:id="@+id/primaryComposeRecycler"
                 android:layout_width="match_parent"