Fix typo in directory structure

Signed-off-by: Robert Drab <robert.drab@huawei.com>

quick-start/downloading-tools-and-sourcecode.rst

@@ -83,6 +83,6 @@ Navigate to *ohos* directory by running the following command:
   * - meta-zephyr
     - Layers required for building Zephyr images.
   * - <various yocto layers>
-    - Layers required to build yacto images.		
+    - Layers required to build yocto images.		
   * - poky
     - Layers required to build customised embedded device images.