refactor(config): initial support for custom error pages

include/config/config.h

@@ -3,12 +3,19 @@
 
 #include <stdbool.h>
 
+typedef struct cws_error_page {
+	unsigned method;
+	const char *path;
+} cws_error_page;
+
 typedef struct cws_vhost {
 	char *domain;
 	char *root;
 	bool ssl;
 	char *cert;
 	char *key;
+	cws_error_page *error_pages;
+	unsigned error_pages_count;
 } cws_vhost_s;
 
 typedef struct cws_config {