[SUGGEST] PlaceholderAPI in cmd-join/leave message + TeamSelector update/request

The title itself already says what the suggestion is about, but explaining better. both `"cmd-join-success"` and `"cmd-leave"` should have placeholderAPI support for obviously adding placeholders. Yes, I know that there is `"{vPrefix}"`, which only returns the vault/luckperms prefix, but if you use a tag/prefix plugin, it is not shown

And regarding the TeamSelector addon, well, you can set the material you want, it will be shown in the hotbar and in the teamselector menu, but see that if you change it to a material that is not colored, it does not change to the team color in the menu, my suggestion about this is: add a `"team-selector-item-hotbar: "`, and a `"team-selector-item-menu: "`, so you can put any item in the hotbar, but in the menu it's still wool or clay with the colors of the available teams, another thing that I would appreciate a lot, would be the possibility to alternate the order of the blocks in the menu, being the current one, or side by side (line only one in the menu with all available colors)

**(Would it be too weird for the TeamSelector addon to have permissions?)**