small fixes

Author: rustagir

source/fundamentals/data-formats/serialization.txt

@@ -354,7 +354,7 @@ After you add the library dependency, you can implement serializers from
 the ``kotlinx-datetime`` library that map your data class field values
 to the expected types in BSON.
 
-In the following example, the driver serializes the fields of
+In this example, the driver serializes the fields of
 the ``Appointment`` data class with the following behavior:
 
 - ``name``: The driver serializes the value as a string.
@@ -371,13 +371,13 @@ the ``Appointment`` data class with the following behavior:
     :language: kotlin
 
 The following example inserts an instance of the ``Appointment`` data
-class into MongoDB:
+class into the ``appointments`` collection:
 
 .. literalinclude:: /examples/generated/KotlinXSerializationTest.snippet.datetime-insertone.kt
     :language: kotlin
 
 In MongoDB, the ``LocalDate`` value is stored as a BSON date, and the
-``time`` field is stored  as a string by default serialization:
+``time`` field is stored as a string by default serialization:
 
 .. code-block:: json