add: repository create webhook

app/services/gitea/repository/webhooks/create_service.rb

@@ -0,0 +1,23 @@
+class Gitea::Repository::Webhooks::CreateService < Gitea::ClientService 
+  attr_reader :token, :owner, :repo, :params 
+  def initialize(token, owner, repo, params) 
+    @token = token
+    @owner = owner 
+    @repo = repo
+    @params = params
+  end
+
+  def call 
+    response = post(url, request_params)
+    render_response(response)
+  end
+
+  private
+  def request_params 
+    Hash.new.merge({token: token, data: params})
+  end
+
+  def url
+    "/repos/#{owner}/#{repo}/hooks".freeze
+  end
+end