Fix curl example refs in docs

The keystone developer docs index page had two links to the same
API examples page: "Service API Examples Using Curl" and
"Admin API Examples Using Curl". This is because the API examples
document had 2 top-level sections.

Partial-Bug: #1283943

Change-Id: I8204268aa482e59f9108d515b69e9c37a12a9e08
Invalid command referenced in federation documentation

The code example to install mod_shib is incorrect as it's
missing the 'install' keyword.

Change-Id: Ie0c4f4bbda56db2a8a2786d5b50c74ab7a2c8a73
Closes-Bug: #1325668
Merge "Invalid command referenced in federation documentation"
Merge "Fix curl example refs in docs"