DOCSP-43247: Update cargo.toml instructions (#129)

(cherry picked from commit 90ea63d)

Author: norareidy

source/fundamentals/runtimes.txt

@@ -44,12 +44,9 @@ Configure the Asynchronous Runtime
 ----------------------------------
 
 The driver uses the ``tokio`` runtime by default, so you can use this runtime without specifying any
-feature flags in your project's ``Cargo.toml`` file. 
-
-You can explicitly choose the ``tokio`` runtime by adding the ``"tokio-runtime"`` feature flag to
-the ``mongodb`` dependency. For more information on installing the driver and adding feature flags,
-including an example that specifies the ``"tokio-runtime"`` feature flag, see the
-:ref:`rust-quick-start-download-and-install` step of the Quick Start.
+feature flags in your project's ``Cargo.toml`` file. For more information on installing the driver
+and configuring your ``Cargo.toml`` file, see the :ref:`rust-quick-start-download-and-install` step
+of the Quick Start.
 
 .. important::
 
@@ -80,32 +77,14 @@ Configure the Synchronous API
 -----------------------------
 
 The driver also provides a blocking, synchronous API.
-To use the synchronous API, add the either the ``"sync"`` or ``"tokio-sync"`` feature flag
-to the ``mongodb`` dependency.
-
-Select from the following tabs to see how to add feature flags for each corresponding crate:
-
-.. tabs::
-
-   .. tab:: sync
-      :tabid: synchronous-api
-
-      .. code-block:: toml
+To use the ``tokio`` synchronous API, add the ``"sync"`` feature flag to
+the ``mongodb`` dependency, as shown in the following example:
 
-         [dependencies.mongodb]
-         version = "{+version+}"
-         default-features = false
-         features = ["sync"]
-
-   .. tab:: tokio-sync
-      :tabid: synchronous-api-tokio
-
-      .. code-block:: toml
+.. code-block:: toml
 
-         [dependencies.mongodb]
-         version = "{+version+}"
-         default-features = false
-         features = ["tokio-sync"]
+   [dependencies.mongodb]
+   version = "{+version+}"
+   features = ["sync"]
 
 Synchronous Code Example
 ~~~~~~~~~~~~~~~~~~~~~~~~
@@ -124,8 +103,8 @@ Use Both Asynchronous and Synchronous APIs
 ------------------------------------------
 
 You can use both asynchronous and synchronous APIs in the same application.
-For example, to enable both ``tokio`` runtimes, you can add the ``tokio`` dependency to your dependencies list, and add the
-``"tokio-sync"`` flag to the ``mongodb`` dependency:
+For example, to enable both ``tokio`` runtimes, you can add the ``tokio`` dependency
+to your dependencies list and add the ``"sync"`` flag to the ``mongodb`` dependency:
 
 .. code-block:: toml
 
@@ -135,7 +114,7 @@ For example, to enable both ``tokio`` runtimes, you can add the ``tokio`` depend
 
    [dependencies.mongodb]
    version = "{+version+}"
-   features = ["tokio-sync"]
+   features = ["sync"]
 
 .. _rust-addtl-info-runtimes:
 

source/quick-start/download-and-install.txt

@@ -76,14 +76,6 @@ Download and Install
 
                [dependencies.mongodb]
                version = "{+version+}"
-               features = ["tokio-runtime"]
-            
-            .. tip::
-
-               The ``tokio`` asynchronous runtime is the driver's default runtime crate
-               and does not require a feature flag. The preceding code example includes
-               the ``"tokio-runtime"`` feature flag to specify the ``tokio`` runtime, but
-               this flag is optional.
 
          .. tab:: Synchronous API
             :tabid: synchronous-api
@@ -95,7 +87,7 @@ Download and Install
 
                [dependencies.mongodb]
                version = "{+version+}"
-               features = ["tokio-sync"]
+               features = ["sync"]
 
       To learn more about asynchronous and synchronous runtimes, see the :ref:`rust-runtimes`
       guide.