Add search tip to kanji search

lib/components/kanji/kanji_search_body.dart

@@ -93,8 +93,16 @@ class _KanjiSearchBodyState extends State<KanjiSearchBody>
                     AnimatedSizeAndFade(
                       fadeDuration: const Duration(milliseconds: 200),
                       sizeDuration: const Duration(milliseconds: 300),
-                      child: _controller.value == 1
+                      child: (_controller.value == 1 && suggestions.isNotEmpty)
                           ? KanjiGrid(suggestions: suggestions)
+                          : (_controller.value == 1)
+                              ? const Text(
+                                  'Type a kanji to start searching',
+                                  style: TextStyle(
+                                    fontSize: 16,
+                                    color: Colors.grey,
+                                  ),
+                                )
                               : const KanjiSearchOptionsBar(),
                     ),
                   ],

lib/components/kanji/kanji_search_body/kanji_search_bar.dart

@@ -53,7 +53,6 @@ class KanjiSearchBarState extends State<KanjiSearchBar> {
       onChanged: (text) => onChanged(),
       onSubmitted: (_) => {},
       decoration: InputDecoration(
-        prefixIcon: const Icon(Icons.search),
         hintText: 'Search',
         border: OutlineInputBorder(
           borderRadius: BorderRadius.circular(10.0),