docs: fix a syntax error in README.rst that was not caught by rstcheck!

Error was: Warning: Inline literal start-string without end-string

Signed-off-by: Stephen L. <lrq3000@gmail.com>

Author: lrq3000

README.rst

@@ -107,7 +107,7 @@ Note: this also works for a single file, just replace "your_folder" by "your_fil
 
 - To update this monitoring database (check for new files, but does not remove files that do not exist anymore - replace ``--append`` with ``--remove`` for the latter):
 
-``pff hash -i "your_folder -d "dbhash.csv" --update --append
+``pff hash -i "your_folder -d "dbhash.csv" --update --append``
 
 - Later, to check which files were corrupted: