chore: correct time diff sign in compression doc

Author: serozhenka

docs/topics/compression.rst

@@ -136,9 +136,9 @@ Window Bits Memory Level Memory usage Size vs. default Time vs. default
 14          7            172 KiB      -7%              +5%
 13          6            100 KiB       -3%             +2%
 **12**      **5**        **64 KiB**   **=**            **=**
-11          4            46 KiB       +10%             +4%
-10          3            37 KiB       +70%             +40%
-9           2            33 KiB       +130%            +90%
+11          4            46 KiB       +10%             -4%
+10          3            37 KiB       +70%             -40%
+9           2            33 KiB       +130%            -90%
 —           —            14 KiB       +350%            —
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