Update docs/source/carrierboard_development.rst

Co-authored-by: barsnick <barsnick@users.noreply.github.com>

Author: mhei

docs/source/carrierboard_development.rst

@@ -111,7 +111,7 @@ Additional notes regarding the content:
 - The digital DT overlay signature is currently not checked by U-Boot or any other software component but this
   is recommended for production use. chargebyte aims to extend the software support for this later.
 
-The idea of the digital DT overlay signature is to ensure that the Device Tree overlay blob is from trusted source and
+The idea of the digital DT overlay signature is to ensure that the Device Tree overlay blob is from a trusted source and
 thus can be loaded and used without damaging the system. The signature can be created using a X.509 certificate
 using e.g. ``openssl cms …`` and thus creating a *detached* signature of the binary DT overlay file.