v0.25.0

• Don't show a runtime warning about the optional ffplay dependency being missing until someone trys to use it
• Documentation improvements
• Python 3.9 support
• Improved efficiency of loading wave files with pydub.AudioSegment.from_file()
• Ensure pydub.AudioSegment().export() always retuns files with a seek position at the beginning of the file
• Added more EQ effects to pydub.scipy_effects (requires scipy to be installed)
• Fix a packaging bug where the LICENSE file was not included in the source distribution
• Add a way to instantiate a pydub.AudioSegment() with a portion of an audio file via pydub.AudioSegment().from_file()