[manual] Update deprecated db.collection.save() method in docs corpus

.save has been deprecated since 4.2 but is still in our docs corpus, this should be updated with one of the following:

• insertOne
• insertMany
• updateOne
• updateMany

"Collection.save() is deprecated. Use insertOne, insertMany, updateOne, or updateMany."

Currently affecting (17) pages.

Example : https://docs.mongodb.com/manual/core/geospatial-indexes/#multi-location-documents-for-2d-indexes