docs(functions): merge manual-only examples and notes into headers

Folds the examples Section 5 carried but the headers did not into each
function's `# EXAMPLE`, and moves the three lines that only looked like
examples -- the two typo-abbreviation notes and rm's /usr/bin/rm fallback --
into `# NOTES`, the label already in use.

Also corrects gi's synopsis, which omitted -l, and documents yt-dlp's
--no-embed-thumbnail in `# ARGUMENTS`.

functions/edit.fish

@@ -41,6 +41,8 @@
 #   edit --terminal --new todo.md
 #   edit --editor=code --clipboard
 #   edit --text="hello world"
+#   edit ~/.config/fish/config.fish
+#   edit --visual notes.txt
 function edit --description 'Open files in a terminal or GUI editor with fallbacks'
     set -l c_head (set_color --bold cyan)
     set -l c_cmd (set_color --bold white)