Update git submodules

* Update plugins/download-commands from branch 'master'
  - Change docs links to actual file extension (.md)
    
    See https://gerrit-review.googlesource.com/83950 for detailed context.
    
    Change-Id: I425285fc81404d49629bf2f468f45c3fc67dd8f9
    
diff --git a/plugins/download-commands b/plugins/download-commands
index 7b41f3a..bdc22b1 160000
--- a/plugins/download-commands
+++ b/plugins/download-commands
@@ -1 +1 @@
-Subproject commit 7b41f3a413b46140b050ae5324cbbcdd467d2b3a
+Subproject commit bdc22b1aa9670548828586d8c022c153dc05d400