fix plurals

Author: milkie

source/includes/extracts-sessions.yaml

@@ -42,8 +42,8 @@ content: |
 
    .. important::
 
-      Do not manually set the ``stmtIds``. MongoDB sets the ``stmtIds``
-      to strictly increasing non-negative number.
+      Do not manually set ``stmtIds``. MongoDB sets the ``stmtIds``
+      to be strictly increasing non-negative numbers.
 
    .. list-table::
       :header-rows: 1
@@ -57,7 +57,7 @@ content: |
 
         - Array of 32-bit integers
 
-        - Array of numbers that uniquely identifies their respective
+        - Array of numbers that uniquely identify their respective
           write operations within the write command.
 ---
 ref: sessions-commands