DOCS-14391 add replWriterMinThreadCount param

Author: andf-mongodb

source/reference/parameters.txt

@@ -1848,11 +1848,40 @@ Replication Parameters
 
    |mongod-only|
 
-   Number of threads to use to apply replicated operations in parallel.
-   Values can range from 1 to 256 inclusive. You can only set
+   Maximum number of threads to use to apply replicated operations in
+   parallel. Values can range from 1 to 256 inclusive. You can only set
    :parameter:`replWriterThreadCount` at startup and cannot change this
    setting with the :dbcommand:`setParameter` command.
 
+   .. seealso::
+
+      :parameter:`replWriterMinThreadCount`
+
+.. parameter:: replWriterMinThreadCount
+
+   .. versionadded:: 4.2.15
+
+   *Type*: integer
+
+   *Default*: 0
+
+   |mongod-only|
+
+   Minimum number of threads to use to apply replicated operations in
+   parallel. Values can range from 0 to 256 inclusive. You can only set
+   :parameter:`replWriterMinThreadCount` at startup and cannot change
+   this setting with the :dbcommand:`setParameter` command.
+
+   Parallel application of replication operations uses up to
+   :parameter:`replWriterThreadCount` threads. If
+   :parameter:`replWriterMinThreadCount` is configured with a value
+   less than :parameter:`replWriterThreadCount`, the thread pool will
+   timeout idle threads until the total count of threads in the thread
+   pool is equal to :parameter:`replWriterMinThreadCount`.
+
+   :parameter:`replWriterMinThreadCount` must be configured with a value
+   that is less than or equal to :parameter:`replWriterThreadCount`.
+
 .. parameter:: rollbackTimeLimitSecs
 
    *Type*: 64-bit integer