Add Documentation for FAA Delays Integration (#14986)

Co-authored-by: Franck Nijhof <git@frenck.dev>

source/_integrations/faadelays.markdown

@@ -0,0 +1,57 @@
+---
+title: FAA Delays
+description: Instructions on how to use FAA Delays data within Home Assistant
+ha_category:
+  - Transport
+ha_release: 2021.3
+ha_iot_class: Cloud Polling
+ha_config_flow: true
+ha_codeowners:
+  - '@ntilley905'
+ha_domain: faadelays
+---
+
+The FAA Delays integration collects and displays information about delays at US Airports based on the
+[FAA's National Airspace System Status](https://www.fly.faa.gov/ois/).
+
+Data measured includes:
+
+- Ground Delays
+- Ground Stops
+- Arrival/Departure Delays
+- Closures
+
+{% include integrations/config_flow.md %}
+
+## Supported Airports
+
+The airport entered must be a valid IATA
+airport code for an airport in the US. You can find this by looking up the 
+FAA Identifier at [Airnav](https://airnav.com/airports/). Officially the FAA
+only supports the airports listed below, but all airports will return data.
+
+Supported airports: BOS, LGA, TEB, EWR, JFK, PHL, PIT, IAD, BWI, DCA, RDU,
+CLT, ATL, MCO, TPA, MCO, FLL, MIA, DTW, CLE, MDW, ORD, IND, CVG, BNA, MEM,
+STL, MCI, MSP, DFW, IAH, DEN, SLC, PHX, LAS, SAN, LAX, SJC, SFO, PDX, SEA
+
+## Additional Delay Information
+
+Each airport added will expose 5 binary sensors, one for each type of delay. Within each sensor there is additional
+information listed as attributes, which depends on the type of delay it is. Each delay type has the attributes
+listed below:
+
+- Ground Delay
+  - Average Delay Time
+  - Delay reason
+- Ground Stop
+  - Expected End Time for stop
+  - Delay reason
+- Arrival/Departure Delay
+  - Minimum delay time
+  - Maximum delay time
+  - Delay trend (increasing/decreasing)
+  - Delay reason
+- Closure
+  - Start of closure (begin)
+  - End of closure (end)
+  - Closure reason