Safe spawn

### What feature do you want to see added? Currently, when you create, recreate, or regenerate a world, then teleport into it, you sometimes end up in the air or in blocks. Would it be possible to add an option to set the worldspawn to a “safe” location (a place where the player won't die) and, in the End, on the obsidian platform? ### Are there any alternatives? It is possible to do this manually with the `/setworldspawn` command, but I am looking to create a system to regenerate some of my worlds by changing the seed each time without the need for human interventio ### Anything else? N/A