PHPLIB-1149: Use consistent terminology when referring to the MongoDB shell in docs (#1106)

Author: GromNaN

docs/reference/method/MongoDBDatabase-createCollection.txt

@@ -26,7 +26,7 @@ Definition
    collection. You may also explicitly create a collection with specific options
    using the :phpmethod:`MongoDB\\Database::createCollection()` method, or using
    :manual:`db.createCollection() </reference/method/db.createCollection>` in
-   the :program:`mongo` shell.
+   the MongoDB shell.
 
    Explicitly creating collections enables you to create
    :manual:`capped collections </core/capped-collections>`, specify

docs/upgrade.txt

@@ -336,7 +336,7 @@ operation, has been removed in favor of explicitly using
 :phpmethod:`MongoDB\\Collection::replaceOne()` (with the ``upsert`` option).
 
 While the ``save`` method does have its uses for interactive environments, such
-as the ``mongo`` shell, it was intentionally excluded from the
+as the MongoDB shell, it was intentionally excluded from the
 `CRUD specification <https://github.com/mongodb/specifications/blob/master/source/crud/crud.rst>`_
 for language drivers. Generally, application code should know if the document
 has an identifier and be able to explicitly insert or replace the document and