samples: Fix typo and outdated guidance

ATRI does not exist, the correct command is ATDI. Also, ATDI "connected" states are 0, 5 or 6.

Author: mikewadsten

samples/remote_manager/send_data_points/README.md

@@ -28,7 +28,9 @@ Make sure the hardware is set up correctly:
    verify that the Connection status LED is blinking or the value of the
    **AI** parameter is **0**.
 3. Make sure the XBee3 cellular device is connected to Digi Remote Manager. To
-   do so, verify that the value of the **RI** parameter is **0**.
+   do so, verify that the value of the **DI** parameter is **0**, **5** or **6**
+   (connected without TLS, connected over TLS, or connected over TLS with authenticated
+   server, respectively).
 
 Run
 ---
@@ -77,4 +79,4 @@ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+SOFTWARE.