docs: explain and comment code

lib/db/isar/main_db.dart

@@ -24,6 +24,11 @@ import 'package:tuple/tuple.dart';
 
 part '../queries/queries.dart';
 
+/*
+ * This file includes the functions that are used to interact with the main database.
+ * To add a new function, add it in the class MainDB.
+ */
+
 class MainDB {
   MainDB._();
   static MainDB? _instance;

lib/route_generator.dart

@@ -165,6 +165,11 @@ import 'package:tuple/tuple.dart';
 
 import 'models/isar/models/contact_entry.dart';
 
+/*
+ * This file contains all the routes for the app.
+ * To add a new route, add it to the switch statement in the generateRoute method.
+ */
+
 class RouteGenerator {
   static const bool useMaterialPageRoute = true;
 

lib/services/coins/coin_service.dart

@@ -34,6 +34,18 @@ import 'package:stackwallet/utilities/enums/coin_enum.dart';
 import 'package:stackwallet/utilities/flutter_secure_storage_interface.dart';
 import 'package:stackwallet/utilities/prefs.dart';
 
+/*
+ * This file implements the CoinServiceAPI abstract class that is used by wallet files to implement the coin specific functionality.
+ * @param coin: The coin type
+ * @param walletId: The wallet id
+ * @param walletName: The wallet name
+ * @param secureStorageInterface: The interface for securely storing data like private keys, mnemonics, passphrases, etc.
+ * @param node: The node to connect to
+ * @param tracker: The transaction notification tracker
+ * @param prefs: The preferences
+ * @return: The coin service API
+ */
+
 abstract class CoinServiceAPI {
   CoinServiceAPI();
 

lib/utilities/block_explorers.dart

@@ -13,6 +13,7 @@ import 'package:stackwallet/db/isar/main_db.dart';
 import 'package:stackwallet/models/isar/models/block_explorer.dart';
 import 'package:stackwallet/utilities/enums/coin_enum.dart';
 
+// Returns the default block explorer URL for the given coin and txid
 Uri getDefaultBlockExplorerUrlFor({
   required Coin coin,
   required String txid,
@@ -59,7 +60,7 @@ Uri getDefaultBlockExplorerUrlFor({
   }
 }
 
-/// returns internal Isar ID for the inserted object/record
+// Returns internal Isar ID for the inserted object/record
 Future<int> setBlockExplorerForCoin({
   required Coin coin,
   required Uri url,
@@ -72,6 +73,7 @@ Future<int> setBlockExplorerForCoin({
   );
 }
 
+// Returns the block explorer URL for the given coin and txid
 Uri getBlockExplorerTransactionUrlFor({
   required Coin coin,
   required String txid,

lib/widgets/choose_coin_view.dart

@@ -24,6 +24,14 @@ import 'package:stackwallet/widgets/background.dart';
 import 'package:stackwallet/widgets/custom_buttons/app_bar_icon_button.dart';
 import 'package:stackwallet/widgets/rounded_white_container.dart';
 
+/*
+ * This widget is used to choose a coin from a list of coins.
+ * @param title: The title of the page.
+ * @param coinAdditional: Additional text to be displayed after the coin name.
+ * @param nextRouteName: The name of the route to be pushed when a coin is selected.
+ * @return A widget that displays a list of coins.
+ */
+
 class ChooseCoinView extends ConsumerStatefulWidget {
   const ChooseCoinView({
     Key? key,