`json.inc` from `sm-ext-json` Still required for includes – but not mentioned in the readme

[StarterX4]

The description says sm-ext-json is optional, but doesn't mention that it's include – json.inc is still required for the plugin compilation.

After I've got a compilation error:

SourcePawn Compiler 1.12.0.7196
Copyright (c) 1997-2006 ITB CompuPhase
Copyright (c) 2004-2024 AlliedModders LLC

/home/starterx4/Pulpit/gity/Kether.pl-L4D2-Server/addons/sourcemod/scripting/include/websocket.inc(7) : error 417: cannot read from file: "json"
     7 | #include <json>
---------^

1 Error.

I've tried changing #include to #tryinclude, thinking it could be a typo, but it only brought even more errors:

SourcePawn Compiler 1.12.0.7196
Copyright (c) 1997-2006 ITB CompuPhase
Copyright (c) 2004-2024 AlliedModders LLC

/home/starterx4/Pulpit/gity/Kether.pl-L4D2-Server/addons/sourcemod/scripting/include/websocket/ws_client.inc(38) : error 139: could not find type "JSON"
    38 |   function void (WebSocket ws, const JSON data, int wireSize);
-----------^

/home/starterx4/Pulpit/gity/Kether.pl-L4D2-Server/addons/sourcemod/scripting/include/websocket/ws_client.inc(128) : error 139: could not find type "JSON"
   128 |   public native void WriteJSON(const JSON data, JSON_WRITE_FLAG write_flg = JSON_WRITE_NOFLAG);
---------------------------------------^

/home/starterx4/Pulpit/gity/Kether.pl-L4D2-Server/addons/sourcemod/scripting/include/websocket/ws_client.inc(128) : error 139: could not find type "JSON_WRITE_FLAG"
   128 |   public native void WriteJSON(const JSON data, JSON_WRITE_FLAG write_flg = JSON_WRITE_NOFLAG);
-------------------------------------------------------^

/home/starterx4/Pulpit/gity/Kether.pl-L4D2-Server/addons/sourcemod/scripting/include/websocket/http.inc(44) : error 139: could not find type "JSON"
    44 |   public native bool PostJson(const JSON json, ResponseCallback fResponse, any value = 0);
--------------------------------------^

/home/starterx4/Pulpit/gity/Kether.pl-L4D2-Server/addons/sourcemod/scripting/include/websocket/http.inc(65) : error 139: could not find type "JSON"
    65 |   public native bool PutJson(const JSON json, ResponseCallback fResponse, any value = 0);
-------------------------------------^

/home/starterx4/Pulpit/gity/Kether.pl-L4D2-Server/addons/sourcemod/scripting/include/websocket/http.inc(76) : error 139: could not find type "JSON"
    76 |   public native bool PatchJson(const JSON json, ResponseCallback fResponse, any value = 0);
---------------------------------------^

6 Errors.

So it was inevitable to add that include to compile my plugin successfully.

[ProjectSky]

It is optional for extensions, but json.inc is required for compiling script plugins. I meant to clarify this earlier—I might have missed it.