tmux: move plugins to config

dot_config/tmux/plugins/tmux-navigate/plugin/tmux-navigate.vim

@@ -0,0 +1,30 @@
+"
+" Intelligently navigate tmux panes and Vim splits using the same keys.
+" This also supports SSH tunnels where Vim is running on a remote host.
+"
+" See https://sunaku.github.io/tmux-select-pane.html for documentation.
+
+function! TmuxNavigateDirections() abort
+  let [y, x] = win_screenpos('.')
+  let h = winheight('.')
+  let w = winwidth('.')
+
+  let can_go_up    = y > 2 " +1 for the tabline
+  let can_go_down  = y + h < &lines - &laststatus
+  let can_go_left  = x > 1
+  let can_go_right = x + w < &columns
+
+  return
+        \ (can_go_up    ? 'U' : '') .
+        \ (can_go_down  ? 'D' : '') .
+        \ (can_go_left  ? 'L' : '') .
+        \ (can_go_right ? 'R' : '')
+endfunction
+
+let progname = substitute($VIM, '.*[/\\]', '', '')
+set title titlestring=%{progname}\ %f\ #%{TmuxNavigateDirections()}
+
+" enable support for setting the window title in regular Vim under tmux
+if &term =~ '^screen' && !has('nvim')
+  execute "set t_ts=\e]2; t_fs=\7"
+endif