python/pickleshare: Wrap README at 72 columns.

Signed-off-by: B. Watson <yalhcru@gmail.com>

python/pickleshare/README

@@ -1,9 +1,10 @@
 PickleShare is a small shelve-like datastore with concurrency support.
 
-Like shelve, a PickleShareDB object acts like a normal dictionary. Unlike
-shelve, many processes can access the database simultaneously. Changing a value
-in database is immediately visible to other processes accessing the same
-database.
+Like shelve, a PickleShareDB object acts like a normal
+dictionary. Unlike shelve, many processes can access the database
+simultaneously. Changing a value in database is immediately visible to
+other processes accessing the same database.
 
-Concurrency is possible because the values are stored in separate files. Hence
-the "database" is a directory where all files are governed by PickleShare.
+Concurrency is possible because the values are stored in separate
+files. Hence the "database" is a directory where all files are
+governed by PickleShare.