Add the Vim joke for first aid

trees/uts-002F.tree

@@ -42,13 +42,15 @@ Most frequently used key mappings is `<leader>` + one character. There are also
 
 \mdblock{First aid}{
 
+> To generate a truly random string, place a new user in front of Vim and ask them to exit
+
 Most of the time, one can use `Esc` + `:qa!` to force quit Vim, with potential loss of unsaved changes.
 
 In most plugin UIs,
 
 - it can be quit with a single `q`, or `Esc` + `:q`, when in despair, try also `Ctrl+c`
-- it will usually enter normal mode first, even in terminals, a single `i` is required to enter insert mode, to acually type something.
-- it might provide visual hints on how to navigate, usually a single number or a character in brackets.
+- it will usually enter normal mode first, even in terminals, a single `i` is required to enter insert mode, to acually type something
+- it might provide visual hints on how to navigate, usually a single number or a character in brackets
 - `g?` or `?` might bring up help on key mappings.
 
 Recording is a powerful feature of Vim, but one can accidentally trigger it with an out-of-order `q`, so one simply need to remember to press `q` again to quit recording if seeing something like `recording @a` in the status bar.