Update legal_hold.py (#239)

Author: annie-payseur

src/code42cli/cmds/legal_hold.py

@@ -30,7 +30,7 @@
 @click.group(cls=OrderedGroup)
 @sdk_options(hidden=True)
 def legal_hold(state):
-    """For adding and removing custodians from legal hold matters."""
+    """Add and remove custodians from legal hold matters."""
     pass