Update git submodules

* Update docs/submodules/bottlenecks from branch 'master'
  - Update document according to Danube release plan

    JIRA: BOTTLENECK-145

    Currently, the docs of Bottlenecks still follow the format
    from Colorado. Some work need to be done regarding reorganizing
    the contents according to the Danube release.

    Change-Id: I4ece51abc558bb7128565125224b5e8579a198f7
    Signed-off-by: yuyang <Gabriel.yuyang@huawei.com>

diff --git a/docs/submodules/bottlenecks b/docs/submodules/bottlenecks
index 4b36a57..566a724 160000 (submodule)
--- a/docs/submodules/bottlenecks
+++ b/docs/submodules/bottlenecks
@@ -1 +1 @@
-Subproject commit 4b36a57727cad302976ee38ad0046a7595339849
+Subproject commit 566a7246d6a8e9451be511ddae84f7067bf013ea