You can see where your keymaps were set with :verbose map, or :verbose nmap for all your normal maps, or :verbose nmap <leader>f for all your normal maps that start with <leader>f. Note that if your keymap was set from lua you will only see “Last set from lua”. To get where in lua, you’ll need to start Neovim in verbose mode nvim -V1. See :help verbose-cmd for more information.
Sometimes people will make blog posts or youtube videos about the most exciting new features in a release. You can always go through the release notes for a given version, but it can be a lot and it’s not necessarily obvious what the implications of a given line are. For example, “$NVIM_APPNAME” is a pretty opaque changelog entry that actually has some really neat applications as a config switcher.
My personal picks for things that have been interesting to me as a user are:
:help exrc)
Yep that’s me, issues welcome 🙂
This is why I mentioned starting in verbose mode
nvim -V1. If you do that you should see the exact line number where the keymap was set from lua.