Improve vims() docstring

Most notably, add example of Vim configuration needed for the function
to work.

dotfiles/bash/main.bashrc

@@ -115,14 +115,28 @@ strip_colors() {
 
 vims() {
     #
-    # Show "abandoned" Vim .swp files in a nice table
+    # List Vim .swp files in a nice table
     #
-    # Call this after crash or poweroff to get back and recover
-    # files open before the fact.  Example:
+    # **Note:** For this ro work, you need to set up Vim to
+    # use same swap directory as assigned below.  this can
+    # be achieved by addoing section such as this to your
+    # .vimrc:
+    #
+    #     if isdirectory($HOME . '/.local/share/vim') == 0
+    #       :silent !mkdir -p ~/.vim/swap >/dev/null 2>&1
+    #     endif
+    #     set directory=./.vim-swap//
+    #     set directory+=~/.local/share/vim/swap//
+    #     set directory+=~/tmp//
+    #     set directory+=.
+    #
+    # Call this after crash or poweroff to remind yourself what
+    # files you were editing before fact.  Example:
     #
     #     2015-07-10 06:10:48.603953758 +0200 ~/TODO.todo
     #
-    # Depends on .swp settings defined in my mydots repo.
+    # This should make it easier to recover after a little
+    # disaster.
     #
     local swap="$HOME/.local/share/vim/swap"
     find "$swap" -type f -print0 \