Add preliminary documentation for database conversion

tests/commands/test_commands.py

@@ -14,7 +14,7 @@ from freqtrade.commands import (start_backtesting_show, start_convert_data, star
                                 start_list_exchanges, start_list_markets, start_list_strategies,
                                 start_list_timeframes, start_new_strategy, start_show_trades,
                                 start_test_pairlist, start_trading, start_webserver)
-from freqtrade.commands.db_commands import start_db_convert
+from freqtrade.commands.db_commands import start_convert_db
 from freqtrade.commands.deploy_commands import (clean_ui_subdir, download_and_install_ui,
                                                 get_ui_download_url, read_ui_version)
 from freqtrade.configuration import setup_utils_configuration
@@ -1462,13 +1462,13 @@ def test_backtesting_show(mocker, testdatadir, capsys):
     assert "Pairs for Strategy" in out
 
 
-def test_start_db_convert(mocker, fee, tmpdir, caplog):
+def test_start_convert_db(mocker, fee, tmpdir, caplog):
     db_src_file = Path(f"{tmpdir}/db.sqlite")
     db_from = f"sqlite:///{db_src_file}"
     db_target_file = Path(f"{tmpdir}/db_target.sqlite")
     db_to = f"sqlite:///{db_target_file}"
     args = [
-        "db-convert",
+        "convert-db",
         "--db-url-from",
         db_from,
         "--db-url",
@@ -1483,5 +1483,5 @@ def test_start_db_convert(mocker, fee, tmpdir, caplog):
     assert not db_target_file.is_file()
     pargs = get_args(args)
     pargs['config'] = None
-    start_db_convert(pargs)
+    start_convert_db(pargs)
     assert db_target_file.is_file()