Updated decoding description (#111)

* Updated decoding description

* Fixed English

* Fixed English

clvm/serialize.py

@@ -1,15 +1,17 @@
 # decoding:
 # read a byte
-# if it's 0xfe, it's nil (which might be same as 0)
+# if it's 0x80, it's nil (which might be same as 0)
 # if it's 0xff, it's a cons box. Read two items, build cons
 # otherwise, number of leading set bits is length in bytes to read size
-# 0-0x7f are literal one byte values
-# leading bits is the count of bytes to read of size
-# 0x80-0xbf is a size of one byte (perform logical and of first byte with 0x3f to get size)
-# 0xc0-0xdf is a size of two bytes (perform logical and of first byte with 0x1f)
-# 0xe0-0xef is 3 bytes ((perform logical and of first byte with 0xf))
-# 0xf0-0xf7 is 4 bytes ((perform logical and of first byte with 0x7))
-# 0xf7-0xfb is 5 bytes ((perform logical and of first byte with 0x3))
+# For example, if the bit fields of the first byte read are:
+#   10xx xxxx -> 1 byte is allocated for size_byte, and the value of the size is 00xx xxxx
+#   110x xxxx -> 2 bytes are allocated for size_byte, and the value of the size 000x xxxx xxxx xxxx
+#   1110 xxxx -> 3 bytes allocated. The size is 0000 xxxx xxxx xxxx xxxx xxxx
+#   1111 0xxx -> 4 bytes allocated.
+#   1111 10xx -> 5 bytes allocated.
+# If the first byte read is one of the following:
+#   1000 0000 -> 0 bytes : nil
+#   0000 0000 -> 1 byte : zero (b'\x00')
 import io
 from .CLVMObject import CLVMObject