Add some documentation

README.md

@@ -1 +1,67 @@
 # FiveM Prometheus
+
+This resource adds a [Prometheus](https://prometheus.io/) endpoint to your FX Server.  
+There are some default metrics available and you can add yours.
+
+## Default metrics
+
+[![Screenshot](https://i.postimg.cc/6qqhFjF5/Selection_887.png)](https://i.postimg.cc/6qqhFjF5/Selection_887.png)
+
+| Name                       	| Type      	| Description                     	|
+|----------------------------	|-----------	|---------------------------------	|
+| fxs_player_count           	| Gauge     	| Number of connected players     	|
+| fxs_player_connections     	| Counter   	| Number of player connections    	|
+| fxs_player_disconnections  	| Counter   	| Number of player disconnections 	|
+| fxs_average_player_latency 	| Gauge     	| Average player latency          	|
+| fxs_players_latency        	| Histogram 	| Players latency                 	|
+| fxs_min_player_ping        	| Gauge     	| Minimum player ping             	|
+| fxs_max_player_ping        	| Gauge     	| Maximum player ping             	|
+
+## Configuration
+
+Convars available:
+
+| Name                    	| Type   	| Default value 	| Description                                                 	|
+|-------------------------	|--------	|---------------	|-------------------------------------------------------------	|
+| prometheus_timeout       	| int   	| 5000          	| Interval in ms to collect data                                |
+| prometheus_auth_enabled  	| int    	| 0              	| Protects the endpoint with credentials if true (`1`)         	|
+| prometheus_login         	| string 	| "admin"        	| Endpoint login                                               	|
+| prometheus_password     	| string 	| "admin"        	| Endpoint password	                                            |
+
+## Prometheus configuration
+
+```
+# A scrape configuration containing exactly one FXS endpoint to scrape.
+scrape_configs:
+  - job_name: 'fxserver'
+    scrape_interval: 60s
+    basic_auth:
+      username: admin
+      password: admin
+    metrics_path: /prometheus/metrics
+    static_configs:
+      - targets: ['127.0.0.1:30120']
+```
+
+## Usage
+
+### Add a new metric
+
+```lua
+--[[
+ * @event prometheus:addMetric
+ *
+ * @param {string} type - The metric type, i.e. Gauge.
+ * @param {string} name - The metric name.
+ * @param {string} description - The metric description.
+ * @param {function} cb - A callback function to update the metric with a method name (i.e. set) and a value.
+]]
+TriggerEvent("prometheus:addMetric", "Gauge", "fxs_gauge_example", "Gauge example.", function(cb)
+    math.randomseed(os.clock())
+    if math.random(0, 1) == 1 then
+      cb("set", 42)
+    else
+      cb("set", 1664)
+    end
+end)
+```