continue adding API docs

Author: W-A-James

src/cursor/abstract_cursor.ts

@@ -73,6 +73,11 @@ export const CursorTimeoutMode = Object.freeze({
  * `cursor.next()`.
  * When set to `'cursorLifetime'`, the deadline applies to the life of the entire cursor.
  *
+ * Depending on the type of cursor being used, this option has different default values.
+ * For non-tailable cursors, this value defaults to `'cursorLifetime'`
+ * For tailable cursors, this value defaults to `'iteration'` since tailable cursors, by
+ * definition can have an arbitrarily long lifetime.
+ *
  * @example
  * # Example showing use of `'iteration'`
  * ```ts

src/cursor/run_command_cursor.ts

@@ -19,9 +19,11 @@ import {
 export type RunCursorCommandOptions = {
   readPreference?: ReadPreferenceLike;
   session?: ClientSession;
-  /** @internal */
+  /** Specifies the time an operation will run until it throws a timeout error. Note that if
+   * `maxTimeMS` is provided in the command in addition to setting `timeoutMS` in the options, then
+   * the original value of `maxTimeMS` will be overwritten. */
   timeoutMS?: number;
-  /** @internal */
+  /** See {@link CursorTimeoutMode} */
   timeoutMode?: CursorTimeoutMode;
   tailable?: boolean;
   awaitData?: boolean;