docs(prerequisites): click install instructions

added click pip install to prerequisites.

Change-Id: I120b1575c562e3b78e0e28e32ec1ff8f9f6d6412
Signed-off-by: Lucas Bruckbauer <lucas.bruckbauer@arm.com>
diff --git a/docs/getting_started/prerequisites.rst b/docs/getting_started/prerequisites.rst
index 9ed8d9b..f5e73c8 100644
--- a/docs/getting_started/prerequisites.rst
+++ b/docs/getting_started/prerequisites.rst
@@ -36,11 +36,11 @@
 
    sudo apt install make libssl-dev flex bison python3 python3-serial python3-pip device-tree-compiler
 
-In addion, install the following python lib using `pip`_:
+In addition, install the following python libraries using `pip`_:
 
 .. code:: shell
 
-   pip3 install fdt
+   pip3 install fdt click
 
 The file kokoro/static_checks.sh runs a series of static code checks into Hafnium's codebase.
 Hafnium follows the linux kernel coding guidelines. As such, the static code checks using the