docs: fix more missing includes

Author: tiennou

include/git2/rebase.h

@@ -11,6 +11,8 @@
 #include "types.h"
 #include "oid.h"
 #include "annotated_commit.h"
+#include "merge.h"
+#include "checkout.h"
 
 /**
  * @file git2/rebase.h

include/git2/status.h

@@ -9,6 +9,8 @@
 
 #include "common.h"
 #include "types.h"
+#include "strarray.h"
+#include "diff.h"
 
 /**
  * @file git2/status.h

include/git2/sys/index.h

@@ -7,6 +7,9 @@
 #ifndef INCLUDE_sys_git_index_h__
 #define INCLUDE_sys_git_index_h__
 
+#include "git2/common.h"
+#include "git2/types.h"
+
 /**
  * @file git2/sys/index.h
  * @brief Low-level Git index manipulation routines

include/git2/sys/merge.h

@@ -7,6 +7,11 @@
 #ifndef INCLUDE_sys_git_merge_h__
 #define INCLUDE_sys_git_merge_h__
 
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/index.h"
+#include "git2/merge.h"
+
 /**
  * @file git2/sys/merge.h
  * @brief Git merge driver backend and plugin routines