(DOCSP-12235) Support query plan cache methods (#47)

* (DOCSP-12235) Support query plan cache methods

Author: zach-carr

source/reference/methods.txt

@@ -667,6 +667,42 @@ standalone and replica set deployments.
 
      - Returns the free cloud monitoring status for your deployment.
 
+Query Plan Cache Methods
+------------------------
+
+.. list-table::
+   :widths: 30 70
+   :header-rows: 1
+
+   * - Method
+
+     - Description
+
+   * - :method:`db.collection.getPlanCache()`
+
+     - Returns an interface to access the query plan cache object and 
+       associated ``PlanCache`` methods for a collection.
+
+   * - :method:`PlanCache.clear()`
+
+     - Removes all cached query plans for a collection.
+
+   * - :method:`PlanCache.clearPlansByQuery()`
+
+     - Clears the cached query plans for the specified 
+       :term:`query shape`.
+
+   * - :method:`PlanCache.help()`
+
+     - Lists the methods available to view and modify a collection’s 
+       query plan cache.
+
+   * - :method:`PlanCache.list()`
+
+     - Returns an array of 
+       :manual:`plan cache entries </core/query-plans/>` 
+       for a collection.
+
 Server Status Methods
 ---------------------