Remove sources/ under docs directory

See #13936.

Signed-off-by: ChaYoung You <yousbe@gmail.com>
Upstream-commit: 3f4eeca68f49a979e2d0af33a7d89bf3ceb62a73
Component: engine

components/engine/docs/articles/https/README.md

@@ -9,7 +9,7 @@ so my process is
 
 $ boot2docker ssh
 $$ git clone https://github.com/docker/docker
-$$ cd docker/docs/sources/articles/https
+$$ cd docker/docs/articles/https
 $$ make cert
 lots of things to see and manually answer, as openssl wants to be interactive
 **NOTE:** make sure you enter the hostname (`boot2docker` in my case) when prompted for `Computer Name`)
@@ -18,7 +18,7 @@ $$ sudo make run
 start another terminal
 
 $ boot2docker ssh
-$$ cd docker/docs/sources/articles/https
+$$ cd docker/docs/articles/https
 $$ make client
 
 the last will connect first with `--tls` and then with `--tlsverify`