updated index docs

docs/indexes.md

@@ -65,7 +65,7 @@ All indexes can be dropped at once with `dropIndexes`
 
 Where `callback` gets two parameters - an error object (if an error occured) and an index information object.
 
-The keys in the index object are the index names and the values are tuples of ioncluded fields.
+The keys in the index object are the index names and the values are tuples of included fields.
 
 For example if a collection has two indexes - as a default an ascending index for the `_id` field and an additonal descending index for `"username"` field, then the index information object would look like the following
 

docs/insert.md

@@ -26,8 +26,22 @@ For example
         console.log("Record added as "+records[0]._id);
     });
 
-Simple update can be done as a regular insert but with the `_id` value set - if a record with this id value exists,
-it will be overwritten.
+If trying to insert a record with an existing `_id` value, then the operation yields in error.
+
+    collection.insert({_id:1}, {safe:true}, function(err, doc){
+        // no error, inserted new document, with _id=1
+        collection.insert({_id:1}, {safe:true}, function(err, doc){
+            // error occured since _id=1 already existed
+        });
+    });
+
+## Save
+
+Shorthand for insert/update is `save` - if `_id` value set, the record is updated if it exists or inserted if it does not; if the `_id` value is not set, then the record is inserted as a new one.
+
+    collection.save({_id:"abc", user:"David"},{safe:true}, callback)
+
+`callback` gets two parameters - an error object (if an error occured) and the record if it was inserted or `1` if the record was updated. 
 
 ## Update