add tmw-related help, do not touch manaplus's
Created by: Helianthella
NPCs can use @@?|@@ links to open the help window and the help window can display pictures so it is useful to display set-by-step help or tutorials.
examples of what can be done:
- make the candor tutorial link to @@?keys|all hotkeys@@
- make the candor tutorial link to @@?levelup|how to level up@@
- make the candor turorial explain the game interface (inventory, chat, shortcuts, spells, ...)
- make the party creation npc explain the social window
- make a troubleshooting npc to solve the most common problems (in this PR I have put buggy server protection)
we could even go as far as building a quest log hybrid using npc and the help window
I first wanted to modify manaplus's built-in help files but I think it is better to use a subfolder for tmw-related tutorials and help and commit my changes to the main manaplus repo instead of overwriting the files