Added some 4XX images

Author: ToBiDi0410

src/4XX/http-400.jpeg

@@ -5,5 +5,5 @@
 - var enduserAdvices = ['Log in with valid credentials', 'Refresh the session'];
 - var professionalReasons = ['Authentication token is invalid or expired', 'The server requires authentication for this resource'];
 - var professionalAdvices = ['Include a valid Authorization header', 'Renew expired authentication tokens'];
-- var img = "data-url:http-4XX.jpeg";
+- var img = "data-url:http-401.jpeg";
 include ../http-error.pug

src/4XX/http-401.jpeg

@@ -6,5 +6,5 @@
 - var enduserAdvices = ['Complete the payment process'];
 - var professionalReasons = ['The request targets a paid service endpoint without valid billing'];
 - var professionalAdvices = ['Include a valid billing token or license'];
-- var img = "data-url:http-4XX.jpeg";
+- var img = "data-url:http-402.jpeg";
 include ../http-error.pug

src/4XX/http-401.pug

@@ -5,5 +5,5 @@
 - var enduserAdvices = ['Access the service with a permitted account'];
 - var professionalReasons = ['Access control rules prohibit the request', 'Authenticated user lacks the required role'];
 - var professionalAdvices = ['Use credentials with appropriate access rights', 'Target a permitted endpoint'];
-- var img = "data-url:http-4XX.jpeg";
+- var img = "data-url:http-403.jpeg";
 include ../http-error.pug

src/4XX/http-402.jpeg

@@ -5,5 +5,5 @@
 - var enduserAdvices = ['Use a valid and known link'];
 - var professionalReasons = ['The endpoint does not exist', 'The route or resource is not defined'];
 - var professionalAdvices = ['Target a valid endpoint', 'Use the current API documentation'];
-- var img = "data-url:http-4XX.jpeg";
+- var img = "data-url:http-404.jpeg";
 include ../http-error.pug