Update git submodules

* Update docs/submodules/parser from branch 'master'
  - Add documents for Relase F

    nfv-toscaprser api document

    JIRA: PARSER-173

    Change-Id: I94603ce8f6698f424f5249ab1008c15199c35845
    Signed-off-by: shangxdy <shang.xiaodong@zte.com.cn>

diff --git a/docs/submodules/parser b/docs/submodules/parser
index d6c75bc..81b39e4 160000 (submodule)
--- a/docs/submodules/parser
+++ b/docs/submodules/parser
@@ -1 +1 @@
-Subproject commit d6c75bcf6eb3dd88a2dee1478236dcf09b73daf9
+Subproject commit 81b39e4d122c1a7566d02348e4d62c882ef4a9aa