DOCS: Simplified the provider URLs (providers) (#2914)

documentation/provider/luadns.md

@@ -0,0 +1,44 @@
+## Configuration
+
+To use this provider, add an entry to `creds.json` with `TYPE` set to `LUADNS`
+along with your [email and API key](https://www.luadns.com/api.html#authentication).
+
+Example:
+
+{% code title="creds.json" %}
+```json
+{
+  "luadns": {
+    "TYPE": "LUADNS",
+    "email": "your-email",
+    "apikey": "your-api-key"
+  }
+}
+```
+{% endcode %}
+
+## Metadata
+This provider does not recognize any special metadata fields unique to LuaDNS.
+
+## Usage
+An example configuration:
+
+{% code title="dnsconfig.js" %}
+```javascript
+var REG_NONE = NewRegistrar("none");
+var DSP_LUADNS = NewDnsProvider("luadns");
+
+D("example.com", REG_NONE, DnsProvider(DSP_LUADNS),
+    A("test", "1.2.3.4")
+);
+```
+{% endcode %}
+
+## Activation
+[Create API key](https://api.luadns.com/api_keys).
+
+## Caveats
+- LuaDNS cannot change the default nameserver TTL in `nameserver_ttl`, it is forced to fixed at 86400("1d").
+This is not the case if you are using vanity nameservers.
+- This provider does not currently support the "FORWARD" and "REDIRECT" record types.
+- The API is available on the LuaDNS free plan, but due to the limit of 30 records, some tests will fail when doing integration tests.