[docs] Mention submodules should be part of the tree, not gitignored

These docs precede the submodules migration.

Bug: None
Change-Id: Idf98cf25cff940a921832e3bda2ea3aa4b03ac16
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6578260
Auto-Submit: Victor Vianna <[email protected]>
Reviewed-by: Josip Sokcevic <[email protected]>
Commit-Queue: Josip Sokcevic <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1464810}
diff --git a/docs/git_submodules.md b/docs/git_submodules.md
index 9347639..c9311cb 100644
--- a/docs/git_submodules.md
+++ b/docs/git_submodules.md
@@ -10,7 +10,7 @@
 
 [TOC]
 
-## A quick introduction to Git submoduldes
+## A quick introduction to Git submodules
 
 [Git submodules](https://git-scm.com/docs/gitsubmodules) are managed via the
 combination of `.gitmodules` files and gitlinks. `.gitmodules` is a text file