Explicitly document lack of thread safety
Explicitly document lack of thread safety
indygreg/python-zstandard,terrelln/python-zstandard,indygreg/python-zstandard,indygreg/python-zstandard,indygreg/python-zstandard,terrelln/python-zstandard,terrelln/python-zstandard,terrelln/python-zstandard