Update README.md

Adding mini documentation

README.md

@@ -1,4 +1,57 @@
 InfluxDB
 ========
 
-Simple PHP client for InfluxDB
+Simple PHP client for [InfluxDB](http://influxdb.org/), an open-source, distributed, time series, events, and metrics database with no external dependencies.
+
+How to install it
+-----------------
+
+The easiest way is to install it via [composer](http://getcomposer.org)
+
+```bash
+composer require crodas/influx-php:\*
+```
+
+How to use it
+-------------
+
+You need to create a client object.
+
+```php
+$client = new \crodas\InfluxPHP\Client(
+   "localhost" /*default*/,
+   8086 /* default */,
+   "root" /* by default */,
+   "root" /* by default */
+);
+```
+
+The first time you should create an database.
+
+```php
+$db = $client->createDatabase("foobar");
+$db->createUser("foo", "bar"); // <-- create user/password
+```
+
+Create data is very simple.
+
+```php
+$db = $client->foobar;
+$db->insert("some label", ['foobar' => 'bar']); // single input
+$db->insert("some label", [
+    ['foobar' => 'bar'],
+    ['foobar' => 'foo'],
+]); // multiple input, this is better :-)
+```
+
+Now you can get the database object and start querying.
+
+```php
+$db = $client->foobar;
+// OR
+$db = $client->getDatabase("foobar");
+
+foreach ($db->query("SELECT * FROM foo;") as $row) {
+    var_dump($row, $row->time);
+}
+```