typo in README.md

Author: cdwijs

README.md

@@ -158,7 +158,7 @@ This will synthesize for the default Vivado part. To synthesise for a specific d
 
 SERV, or rather the Servant SoC, can run the [Zephyr RTOS](https://www.zephyrproject.org). The Servant-specific drivers and BSP is located in the zephyr subdirectory of the SERV repository. In order to use Zephyr on Servant, a project directory structure must be set up that allows Zephyr to load the Servant-specific files as a module.
 
-First, the Zephyr SDK and the "west" build too must be installed. The [Zephyr getting started guide](https://docs.zephyrproject.org/latest/getting_started/index.html) describes these steps in more detail.
+First, the Zephyr SDK and the "west" build tool must be installed. The [Zephyr getting started guide](https://docs.zephyrproject.org/latest/getting_started/index.html) describes these steps in more detail.
 
 Assuming that SERV was installed into `$WORKSPACE/fusesoc_libraries/serv` as per the prerequisites, run the following command to make the workspace also work as a Zephyr workspace.