(Added) the configuration to the application.

Moved database file to the user data directory.

tui_rsync/config/__init__.py

@@ -0,0 +1,2 @@
+from config.app import App
+

tui_rsync/config/app.py

@@ -0,0 +1,52 @@
+################################################################################
+# Copyright (C) 2023 Kostiantyn Klochko <kostya_klochko@ukr.net>               #
+#                                                                              #
+# This file is part of tui-rsync.                                              #
+#                                                                              #
+# tui-rsync is free software: you can redistribute it and/or modify it under   #
+# uthe terms of the GNU General Public License as published by the Free        #
+# Software Foundation, either version 3 of the License, or (at your option)    #
+# any later version.                                                           #
+#                                                                              #
+# tui-rsync is distributed in the hope that it will be useful, but WITHOUT ANY #
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS    #
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more        #
+# details.                                                                     #
+#                                                                              #
+# You should have received a copy of the GNU General Public License along with #
+# tui-rsync. If not, see <https://www.gnu.org/licenses/>.                      #
+################################################################################
+
+import platformdirs
+import os
+
+class App:
+    """
+    Configuration of the tui-rsync
+    """
+    __APP_NAME = "tui-rsync"
+    __APP_AUTHOR = "KKlochko"
+    __DB_NAME = "sync.db"
+
+    def get_db_path(self):
+        path = platformdirs.user_data_path(
+            self.__APP_NAME,
+            self.__APP_AUTHOR,
+            self.__DB_NAME
+        )
+        App.safe_create_path(self.get_data_dir())
+        return path
+
+    def get_data_dir(self):
+        return platformdirs.user_data_dir(
+            self.__APP_NAME,
+            self.__APP_AUTHOR,
+        )
+
+    @staticmethod
+    def safe_create_path(path):
+        """
+        Create path's folders if they do not exist
+        """
+        if not os.path.exists(path):
+            os.makedirs(path)