boards: sparkfun: Update board name in doc/index.rst

Fix board name in documentation file doc/index.rst

Signed-off-by: Teresa Zepeda Ventura <teresa.zvent@gmail.com>

boards/sparkfun/thing_plus_matter_mgm240p/doc/index.rst

@@ -1,6 +1,6 @@
 .. _sparkfun_thing_plus_mgm240p:
 
-SPARKFUN THING PLUS MATTER
+SparkFun Thing Plus Matter
 ###########################
 
 Overview
@@ -15,7 +15,7 @@ ARM Cortex®-M33F processor with excellent low power capabilities.
    :align: center
    :alt: MGM240P Sparkfun Think Plus Matter
 
-   xG24-MGM240P (image courtesy of Sparkfun)
+   MGM240P Sparkfun Think Plus Matter (image courtesy of Sparkfun)
 
 Hardware
 ********
@@ -81,7 +81,7 @@ means Pin number 2 on PORTA, as used in the board's datasheets and manuals.
 +-------+-------------+-------------------------------------+
 
 The default configuration can be found in
-:zephyr_file:`boards/silabs/sparkfun_thing_plus_mgm240p/sparkfun_thing_plus_mgm240p_defconfig`
+:zephyr_file:`boards/silabs/sparkfun_thing_plus_matter_mgm240p/sparkfun_thing_plus_matter_mgm240p_defconfig`
 
 System Clock
 ============
@@ -128,7 +128,7 @@ terminal session:
 
 .. code-block:: console
 
-   Hello World! _sparkfun_thing_plus_mgm240p
+   Hello World! _sparkfun_thing_plus_matter_mgm240p
 
 Bluetooth
 =========
@@ -146,7 +146,7 @@ this example.
 
 .. zephyr-app-commands::
    :zephyr-app: samples/bluetooth/observer
-   :board: sparkfun_thing_plus_mgm240p
+   :board: sparkfun_thing_plus_matter_mgm240p
    :goals: build
 
 .. _EFR32MG24 Website: