added an example of collecting file records

    test001.txt True Test file 1     False

    test002.txt True Test file 2     False

`FileRecorder` inherits from `list`.

Therefore, if you are collecting records from subprocesses,

here is the way to combine records:

.. code-block:: python

    :linenos:

    >>> from csst_common.file_recorder import FileRecorder

    >>> fr1 = FileRecorder()

    >>> fr1.add_record(filepath="test1.txt", db=False, comment="test file 1")

    >>> fr2 = FileRecorder()

    >>> fr2.add_record(filepath="test2.txt", db=False, comment="test file 2")

    >>> fr_all = FileRecorder([*fr1, *fr2])

    >>> fr_all.pprint_all()

    <FileRecorder length=2>

     filepath   db    comment   existence

    --------- ----- ----------- ---------

    test1.txt False test file 1     False

    test2.txt False test file 2     False

``csst_common.logger.get_logger()``

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