Added public files
Roughly added all public files. Probably missed some, though.
diff --git a/doc/hook/modify_command b/doc/hook/modify_command
new file mode 100644
index 0000000..f478312
--- /dev/null
+++ b/doc/hook/modify_command
@@ -0,0 +1,61 @@
+SYNOPSIS
+ #include <sys/driver_hooks.h>
+
+ set_driver_hook(H_MODIFY_COMMAND, value)
+
+ <value> being:
+
+ int|string <closure>(string cmd, object player)
+ int|string <name>(string cmd)
+ <mapping>
+
+DESCRIPTION
+ Optional hook to modify commands (both entered or given by a
+ call to command()) before the parser sees them (this includes
+ special commands like 'status').
+
+ Hook setting can be any closure, the name of the function to
+ call in the object, or a mapping.
+
+ For interactives this hook is used only if the interactive
+ object has no command modifier already set by the efun
+ set_modify_command().
+
+ If the hook is a closure, it is called with the entered
+ command as first, and the command giving player as second
+ argument. Lambda closures are bound to the command giving player,
+ unbound-lambda closures remain unbound.
+
+ If the hook is a string, it is used as the name of an lfun
+ in the command giving player, which is called with the command
+ as argument.
+
+ If the hook is a mapping, it is queried with the given command
+ as index, and the data retrieved is used as new command
+ (defaults to 0 if no data is stored for a given command). If
+ an entry is a closure instead of a string, it is called as
+
+ int|string <closure>(string cmd, object player)
+
+ and the result from the call is used as 'the' command.
+
+ The result is treated equal in all three cases:
+ - If the result is a string, it is the new command to execute
+ instead of the given one. Note that it is not possible to
+ make several commands from one this way!
+ - If the result is a non-zero number, the given command is to
+ be ignored. In case of the closure/lfun setting this may
+ mean that the closure/lfun already executed it.
+ - If the result is 0, the originally given command is to be
+ used.
+
+ It is possible for the hook to change the command giver
+ (this_player()) for the execution of the command. This means that
+ even though the commands are execute for the original commandgiver,
+ this_player() will return the changed commandgiver.
+
+HISTORY
+
+SEE ALSO
+ hooks(C), command(H), modify_command_fname(H), notify_fail(H),
+ send_notify_fail(H)