Doc tweaks, refs #2682

doc/04-schema.md

@@ -676,10 +676,10 @@ The following options are supported:
 * **preferred-install:** Defaults to `auto` and can be any of `source`, `dist` or
   `auto`. This option allows you to set the install method Composer will prefer to
   use.
-* **github-protocols:** Defaults to `["git", "https"]`. A list of protocols to
+* **github-protocols:** Defaults to `["git", "https", "ssh"]`. A list of protocols to
   use when cloning from github.com, in priority order. You can reconfigure it to
-  prioritize the https protocol if you are behind a proxy or have somehow bad
-  performances with the git protocol.
+  for example prioritize the https protocol if you are behind a proxy or have somehow
+  bad performances with the git protocol.
 * **github-oauth:** A list of domain names and oauth keys. For example using
   `{"github.com": "oauthtoken"}` as the value of this option will use `oauthtoken`
   to access private repositories on github and to circumvent the low IP-based

src/Composer/Config.php

@@ -206,7 +206,7 @@ class Config
 
             case 'github-protocols':
                 if (reset($this->config['github-protocols']) === 'http') {
-                    throw new \RuntimeException('The http protocol for github is not available anymore, update your config\'s github-protocols to use "https" or "git" or "ssh"');
+                    throw new \RuntimeException('The http protocol for github is not available anymore, update your config\'s github-protocols to use "https", "git" or "ssh"');
                 }
 
                 return $this->config[$key];