Fix long option format on docs.podman.io

Escape the two dashes, otherwise they are combined into one long dash.
I tested that this change is safe and still renders correctly on github
and with the man pages.

This commit also contains a small change to make it build locally.
Assuming you have the dependencies installed you can do:
```
cd docs
make html
```
Preview the html files in docs/build/html with
`python -m http.server 8000 --directory build/html`.

Fixes containers/podman.io#373

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

1 files changed, 4 insertions, 4 deletions

diff --git a/docs/source/markdown/podman-system-connection-add.1.md b/docs/source/markdown/podman-system-connection-add.1.md
index 32c16d6a1..5f5d2bc7d 100644
--- a/docs/source/markdown/podman-system-connection-add.1.md
+++ b/docs/source/markdown/podman-system-connection-add.1.md
@@ -15,21 +15,21 @@ The user will be prompted for the remote ssh login password or key file pass phr
 
 ## OPTIONS
 
-#### **--default**=*false*, **-d**
+#### **\-\-default**=*false*, **-d**
 
 Make the new destination the default for this user.
 
-#### **--identity**=*path*
+#### **\-\-identity**=*path*
 
 Path to ssh identity file. If the identity file has been encrypted, Podman prompts the user for the passphrase.
 If no identity file is provided and no user is given, Podman defaults to the user running the podman command.
 Podman prompts for the login password on the remote server.
 
-#### **--port**=*port*, **-p**
+#### **\-\-port**=*port*, **-p**
 
 Port for ssh destination. The default value is `22`.
 
-#### **--socket-path**=*path*
+#### **\-\-socket-path**=*path*
 
 Path to the Podman service unix domain socket on the ssh destination host