update doc server to ctorm 1.8.1

Signed-off-by: ngn <ngn@ngn.tf>

doc/inc/file.h

@@ -0,0 +1,10 @@
+#pragma once
+#include <stdint.h>
+
+typedef struct {
+  char   *content;
+  int64_t size;
+} file_t;
+
+file_t *file_load(int dirfd, char *path);
+void    file_free(file_t *file);