docs: fix git submodule update command

Closes https://github.com/espressif/esp-idf/issues/2584

diff --git a/docs/en/versions.rst b/docs/en/versions.rst
index 5d6530cb680b5e11b8f20612c1b5955f193ec102..0c36d73022d14432b9711e9f24c48ecc7148f467 100644 (file)
--- a/docs/en/versions.rst
+++ b/docs/en/versions.rst
@@ -166,7 +166,7 @@ For example, to follow the branch for ESP-IDF v3.1, including any bugfixes for f
   git fetch
   git checkout release/v3.1
   git pull
-  git submodule --update --init --recursive
+  git submodule update --init --recursive
 
 Each time you ``git pull`` this branch, ESP-IDF will be updated with fixes for this release.