I've recently switched my "notes.txt" buffer in (neo)vim to markdown ("notes.md) - along with a slightly more magical syntax plug-in - and I'm pleasantly surprised by the quality of life improvements from having multiple code/script snippets highlighted in-line (eg: ```SQL (... Snippet...) ``` in a paragraph followed by some notes and a block of bash etc).

But I rarely execute the blocks in / from vim - I do a bit of copy-pasting though (I don't generally fit a terminal buffer/window in vim, I use a separate window with gnome-terminal or Sakura. I tried term-in-vim, but didn't quite like the flow. Maybe I should try again).