minimal profiles docs 📝

docs/departures.md

@@ -31,7 +31,7 @@ With `opt`, you can override the default options, which look like this:
 
 ## Response
 
-*Note:* As stated in the [*Friendly Public Transport Format* `1.0.1`](https://github.com/public-transport/friendly-public-transport-format/tree/1.0.1), the `when` include the current delay. The `delay` field, if present, expresses how much the former differs from the schedule.
+*Note:* As stated in the [*Friendly Public Transport Format* `1.0.1`](https://github.com/public-transport/friendly-public-transport-format/tree/1.0.1), the `when` field includes the current delay. The `delay` field, if present, expresses how much the former differs from the schedule.
 
 You may pass the `journeyId` field into [`journeyLeg(ref, lineName, [opt])`](journey-leg.md) to get details on the vehicle's journey.
 

docs/journeys.md

@@ -199,7 +199,7 @@ The response may look like this:
 } ]
 ```
 
-If you pass `tickets: true`, each `journey` will have a tickets array that looks like this:
+Some [profiles](../p) are able to parse the ticket information, if returned by the API. For example, if you pass `tickets: true` with the [VBB profile](../p/vbb), each `journey` will have a tickets array that looks like this:
 
 ```js
 [ {

p/readme.md

@@ -0,0 +1,15 @@
+# Profiles
+
+This directory contains specific customisations for each endpoint, called *profiles*. They **parse data from the API differently, add additional information, or enable non-default methods** (such as [`journeyLeg`](../docs/journey-leg.md)) if they are supported.
+
+Each profile has it's own directory. It will be passed into `hafas-client` and is expected to be in a certain structure:
+
+```js
+const createClient = require('hafas-client')
+const someProfile = require('hafas-client/p/some-profile')
+
+// create a client with the profile
+const client = createClient(dbProfile)
+
+// use it to query data…
+```