fix(Documentation): Adding documentation

README.md

@@ -1,4 +1,64 @@
 # spark-monitoring
 
-A tool to extract metrics from Spark Jobs
+A tool to extract metrics from Spark Applications, it applies to Streaming and Jobs.
 
+## Current Status
+
+Stable.
+
+## Installation
+
+```sh
+npm install spark-monitoring
+```
+
+## Features
+
+* Extract metrics from Streaming Jobs;
+* Extract metrics from Normal Jobs;
+* Send these metrics to Zabbix.
+
+## Send metrics to Zabbix
+
+To get usage details, type this:
+
+```sh
+zabbix-spark-monitor --help
+```
+
+## To use the tool on your application
+
+Import the required class as follow:
+```javascript
+import { SparkMonitoring } from '../../lib/spark-monitoring';
+```
+
+And use the method `getApplicationStats` to get statistics for an specific application.
+
+The output follow this example: 
+```json
+{
+  "allocatedMB": 5632,
+  "allocatedVCores": 4,
+  "elapsedTime": 1050926592,
+  "id": "application_1569147216125_1386",
+  "jobStats": [
+    {
+      "max": 25,
+      "mean": 17.6,
+      "min": 11,
+      "name": "DataCollection",
+      "window": 156
+    }
+  ],
+  "memorySeconds": 5918796398,
+  "name": "51-minimum-gain",
+  "pendingRecords": 2561,
+  "processedRecords": 951,
+  "runningContainers": 4,
+  "runningJobs": 1,
+  "streaming": true,
+  "totalDelay": 30000,
+  "vcoreSeconds": 4203689
+}
+```