Fix capitalization of ImGuiID in comment. (#8283)

imgui.h

@@ -2895,7 +2895,7 @@ struct ImGuiSelectionBasicStorage
     IMGUI_API void  Clear();                                    // Clear selection
     IMGUI_API void  Swap(ImGuiSelectionBasicStorage& r);        // Swap two selections
     IMGUI_API void  SetItemSelected(ImGuiID id, bool selected); // Add/remove an item from selection (generally done by ApplyRequests() function)
-    IMGUI_API bool  GetNextSelectedItem(void** opaque_it, ImGuiID* out_id); // Iterate selection with 'void* it = NULL; ImGuiId id; while (selection.GetNextSelectedItem(&it, &id)) { ... }'
+    IMGUI_API bool  GetNextSelectedItem(void** opaque_it, ImGuiID* out_id); // Iterate selection with 'void* it = NULL; ImGuiID id; while (selection.GetNextSelectedItem(&it, &id)) { ... }'
     inline ImGuiID  GetStorageIdFromIndex(int idx)              { return AdapterIndexToStorageId(this, idx); }  // Convert index to item id based on provided adapter.
 };