Appended the aliases.json.default with the gamemodes, added "get_gamemodes" and "aliases gamemodes"

[frostyboskitzo]

Just a little helper to remind an on-again-off-again server owner and his various mods/captains what the game modes are for the switchmap command.

This code is currently running on our community server (Bowels).

Running aliases returns the normal list, including this:

This block outputs as a result of ".aliases" or ".aliases gamemodes" by itself.

It shows up in the help section:

The example file "aliases.json.example" now includes the full list.

There is merit for this to be added as either:

A) It's own json - gamemodes.json.example, for example which would be a little more work, but perhaps nicer - then gamemodes could be it's own command

B) Append the information to the info command, which is how I used to have it in my 2021 branch of the code; but this didn't display as nicely.

C) Append the information somewhere else, like the lists section, and have a separate command to invoke the prompt for gamemodes.

As a UX improvement, it would be good once this is implemented, to have detection on switchmap/map commands where the game_mode is malformed, it spits out the valid gamemodes to the user.