Update README to include latest zippy.py args

Signed-off-by: Jacob Torrey <jacob@thinkst.com>

README.md

@@ -31,15 +31,17 @@ Here are each of them compared with both the LZMA and zlib detector across the t
 ZipPy will read files passed as command-line arguments, or will read from stdin to allow for piping of text to it. 
 ```
 $ python3 zippy.py -h
-usage: zippy.py [-h] [-e {zlib,lzma}] [-s | sample_files ...]
+usage: zippy.py [-h] [-p P] [-e {zlib,lzma,brotli,ensemble}] [-s | sample_files ...]
 
 positional arguments:
-  sample_files    Text file(s) containing the sample to classify
+  sample_files          Text file(s) containing the sample to classify
 
 options:
-  -h, --help      show this help message and exit
+  -h, --help            show this help message and exit
-  -e {zlib,lzma}  Which compression engine to use: lzma or zlib
+  -p P                  Preset to use with compressor, higher values are slower but provide better compression
-  -s              Read from stdin until EOF is reached instead of from a file
+  -e {zlib,lzma,brotli,ensemble}
+                        Which compression engine to use: lzma, zlib, brotli, or an ensemble of all engines
+  -s                    Read from stdin until EOF is reached instead of from a file
 $ python3 zippy.py samples/human-generated/about_me.txt 
 samples/human-generated/about_me.txt
 ('Human', 0.06013429262166636)