docs(NODE-6458): document CSOT for explicit encryption (#4302)

Author: baileympearson

src/client-side-encryption/client_encryption.ts

@@ -866,9 +866,36 @@ export interface ClientEncryptionOptions {
    */
   tlsOptions?: CSFLEKMSTlsOptions;
 
-  /** @internal TODO(NODE-5688): make this public
+  /**
+   * @experimental
    *
    * The timeout setting to be used for all the operations on ClientEncryption.
+   *
+   * When provided, `timeoutMS` is used as the timeout for each operation executed on
+   * the ClientEncryption object.  For example:
+   *
+   * ```typescript
+   * const clientEncryption = new ClientEncryption(client, {
+   *  timeoutMS: 1_000
+   *  kmsProviders: { local: { key: '<KEY>' } }
+   * });
+   *
+   * // `1_000` is used as the timeout for createDataKey call
+   * await clientEncryption.createDataKey('local');
+   * ```
+   *
+   * If `timeoutMS` is configured on the provided client, the client's `timeoutMS` value
+   * will be used unless `timeoutMS` is also provided as a client encryption option.
+   *
+   * ```typescript
+   * const client = new MongoClient('<uri>', { timeoutMS: 2_000 });
+   *
+   * // timeoutMS is set to 1_000 on clientEncryption
+   * const clientEncryption = new ClientEncryption(client, {
+   *  timeoutMS: 1_000
+   *  kmsProviders: { local: { key: '<KEY>' } }
+   * });
+   * ```
    */
   timeoutMS?: number;
 }