doc: small render fix for nRF54L15 page

fixed the directive to make sure the command renders correctly

Signed-off-by: Anna Wojdylo <anna.wojdylo@nordicsemi.no>
diff --git a/boards/nordic/nrf54l15dk/doc/index.rst b/boards/nordic/nrf54l15dk/doc/index.rst
index e4ad1e8..6d06177 100644
--- a/boards/nordic/nrf54l15dk/doc/index.rst
+++ b/boards/nordic/nrf54l15dk/doc/index.rst
@@ -100,8 +100,12 @@
 to be built as multicore configuration with code snippet called ``vpr_launcher``
 for the application core.
 
-Enter the following command to compile ``hello_world`` for the FLPR core::
- west build -p -b nrf54l15dk/nrf54l15/cpuflpr --sysbuild -- -DSB_VPR_LAUNCHER=y
+Enter the following command to compile ``hello_world`` for the FLPR core:
+
+.. code-block:: console
+
+   west build -p -b nrf54l15dk/nrf54l15/cpuflpr --sysbuild -- -DSB_VPR_LAUNCHER=y
+
 
 Flashing
 ========