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, 8 insertions, 8 deletions

diff --git a/docs/source/markdown/podman-login.1.md b/docs/source/markdown/podman-login.1.md
index 274869042..c7779788f 100644
--- a/docs/source/markdown/podman-login.1.md
+++ b/docs/source/markdown/podman-login.1.md
@@ -28,41 +28,41 @@ For more details about format and configurations of the auth.json file, please r
 
 ## OPTIONS
 
-#### **--password**, **-p**=*password*
+#### **\-\-password**, **-p**=*password*
 
 Password for registry
 
-#### **--password-stdin**
+#### **\-\-password-stdin**
 
 Take the password from stdin
 
-#### **--username**, **-u**=*username*
+#### **\-\-username**, **-u**=*username*
 
 Username for registry
 
-#### **--authfile**=*path*
+#### **\-\-authfile**=*path*
 
 Path of the authentication file. Default is ${XDG\_RUNTIME\_DIR}/containers/auth.json.
 
 Note: You can also override the default path of the authentication file by setting the REGISTRY\_AUTH\_FILE
 environment variable. `export REGISTRY_AUTH_FILE=path`
 
-#### **--get-login**
+#### **\-\-get-login**
 
 Return the logged-in user for the registry.  Return error if no login is found.
 
-#### **--cert-dir**=*path*
+#### **\-\-cert-dir**=*path*
 
 Use certificates at *path* (\*.crt, \*.cert, \*.key) to connect to the registry.
 Default certificates directory is _/etc/containers/certs.d_. (This option is not available with the remote Podman client)
 
-#### **--tls-verify**=*true|false*
+#### **\-\-tls-verify**=*true|false*
 
 Require HTTPS and verify certificates when contacting registries (default: true). If explicitly set to true,
 then TLS verification will be used. If set to false, then TLS verification will not be used. If not specified,
 TLS verification will be used unless the target registry is listed as an insecure registry in registries.conf.
 
-#### **--help**, **-h**
+#### **\-\-help**, **-h**
 
 Print usage statement