adding timeout

Signed-off-by: Thomas Poignant <thomas.poignant@gofeatureflag.org>

Author: thomaspoignant

guideline/dynamic-context-provider.md

@@ -15,6 +15,7 @@ An OFREP server provider implementation must, at the time of creation, accept at
   This must be the base of the URL pointing before the `/ofrep` namespace of the API.
   - In the constructor, the provider should check if the `baseURL` is a valid URL and return an error if the URL is invalid.
 - `headers`: The headers to use when calling the OFREP endpoints *(e.g.:`Authorization`, Custom headers, etc ...)*.
+- `timeout`: The time to wait before abording the HTTP request. A 10 seconds default should be taken if the option is not provided.
 
 ## Evaluation
 When an evaluation function is called the server provider will make a `POST` request to the `/ofrep/v1/evaluate/flags/{key}` endpoint *(where `{key}` is the flag name), with the evaluation context in the body.