ways to do note-taking within Vim or Neovim

• txtfmt — allows you to do "rich text" highlighting in Vim
• vimwiki
• vimnote
• vikibase_vim, successor to viki_vim — wiki-like notes

To-do organizers

• vim-orgmode
• vim-dotoo
• TODO: some options in neovim

Outliners

• Vimliner