Add rate limiting to Wikipedia and BraveSearch APIs

Closes #133

lib/wikipedia/api.ex

@@ -15,6 +15,7 @@ defmodule Wikipedia.API do
         user_agent: config.user_agent
       )
       |> Req.Request.merge_options(config.req_options)
+      |> Req.RateLimiter.attach(name: :wikipedia, cooldown: config.api_cooldown)
       |> Req.Request.append_request_steps(log_attempt: &log_attempt/1)
       |> Req.Request.append_response_steps(log_error: &log_error/1)
       |> Req.merge(
@@ -52,6 +53,7 @@ defmodule Wikipedia.API do
         user_agent: config.user_agent
       )
       |> Req.Request.merge_options(config.req_options)
+      |> Req.RateLimiter.attach(name: :wikipedia, cooldown: config.api_cooldown)
       |> Req.Request.append_request_steps(log_attempt: &log_attempt/1)
       |> Req.Request.append_response_steps(log_error: &log_error/1)
       |> Req.merge(url: "/api/rest_v1/page/summary/#{URI.encode(title)}")
@@ -78,6 +80,7 @@ defmodule Wikipedia.API do
         user_agent: config.user_agent
       )
       |> Req.Request.merge_options(config.req_options)
+      |> Req.RateLimiter.attach(name: :wikipedia, cooldown: config.api_cooldown)
       |> Req.Request.append_request_steps(log_attempt: &log_attempt/1)
       |> Req.Request.append_response_steps(log_error: &log_error/1)
       |> Req.merge(

lib/wikipedia/config.ex

@@ -1,11 +1,13 @@
 defmodule Wikipedia.Config do
   @type t :: %__MODULE__{
           user_agent: String.t(),
-          req_options: Keyword.t()
+          req_options: Keyword.t(),
+          api_cooldown: non_neg_integer()
         }
 
   defstruct user_agent: "change me",
-            req_options: []
+            req_options: [],
+            api_cooldown: 1000
 
   @schema NimbleOptions.new!(
             user_agent: [
@@ -17,6 +19,11 @@ defmodule Wikipedia.Config do
               type: :keyword_list,
               required: false,
               default: []
+            ],
+            api_cooldown: [
+              type: :integer,
+              required: false,
+              default: 1000
             ]
           )