New provider: Linode (#268)

docs/_providers/linode.md

@@ -0,0 +1,57 @@
+---
+name: Linode
+title: Linode Provider
+layout: default
+jsId: LINODE
+---
+# Linode Provider
+
+## Configuration
+In your credentials file, you must provide your
+[Linode Personal Access Token](https://cloud.linode.com/profile/tokens)
+
+{% highlight json %}
+{
+  "linode": {
+    "token": "your-linode-personal-access-token"
+  }
+}
+{% endhighlight %}
+
+## Metadata
+This provider does not recognize any special metadata fields unique to Linode.
+
+## Usage
+Example Javascript:
+
+{% highlight js %}
+var REG_NONE = NewRegistrar('none', 'NONE')
+var LINODE = NewDnsProvider("linode", "LINODE");
+
+D("example.tld", REG_NONE, DnsProvider(LINODE),
+    A("test","1.2.3.4")
+);
+{%endhighlight%}
+
+## Activation
+[Create Personal Access Token](https://cloud.linode.com/profile/tokens)
+
+## Caveats
+Linode does not allow all TTLs, but only a specific subset of TTLs. The following TTLs are supported
+([source](https://github.com/linode/manager/blob/master/src/domains/components/SelectDNSSeconds.js)):
+
+- 300
+- 3600
+- 7200
+- 14400
+- 28800
+- 57600
+- 86400
+- 172800
+- 345600
+- 604800
+- 1209600
+- 2419200
+
+The provider will automatically round up your TTL to one of these values. For example, 600 seconds would become 3600
+seconds, but 300 seconds would stay 300 seconds.