doc: Fixed consistency of MCUboot

Fixed the consistency of the case used in the term MCUboot.

Signed-off-by: Francesco Servidio <francesco.servidio@nordicsemi.no>
diff --git a/docs/readme-espressif.md b/docs/readme-espressif.md
index fa72fb3..0f6f5ac 100644
--- a/docs/readme-espressif.md
+++ b/docs/readme-espressif.md
@@ -19,7 +19,7 @@
 1. Install additional packages required for development with MCUboot:
 
 ```
-  cd ~/mcuboot  # or to your directory where mcuboot is cloned
+  cd ~/mcuboot  # or to your directory where MCUboot is cloned
   pip3 install --user -r scripts/requirements.txt
 ```