DOCSP-15210 document fixDottedHashIndex option (#130)

* DOCSP-15210 document fixDottedHashIndex option

* Update source/mongorestore.txt

Co-authored-by: Nick Villahermosa <nick.villahermosa@mongodb.com>

---------

Co-authored-by: Nick Villahermosa <nick.villahermosa@mongodb.com>

Author: kanchana-mongodb

source/mongorestore.txt

@@ -864,6 +864,12 @@ Options
    specified in the corresponding :binary:`~bin.mongodump` output.
 
 
+.. option:: --fixDottedHashIndex 
+
+   Creates all :manual:`hashed indexes 
+   </core/indexes/index-types/index-hashed/>` on dotted fields as 
+   single field ascending indexes on the destination database.
+
 .. option:: --noOptionsRestore
 
    Prevents ``mongorestore`` from setting the collection options,