Added plugin functionality and updated help file

plugin/indent-guides.vim

@@ -0,0 +1,59 @@
+" Author:   Nate Kane <nathanaelkane AT gmail DOT com>
+" Homepage: http://github.com/nathanaelkane/vim-indent-guides
+
+function! s:IndentGuidesToggle()
+  let g:IndentGuides_matches =
+  \ exists('g:IndentGuides_matches') ? g:IndentGuides_matches : []
+
+  if empty(g:IndentGuides_matches)
+    IndentGuidesEnable
+  else
+    IndentGuidesDisable
+  endif
+endfunction
+
+function! s:IndentGuidesEnable()
+  IndentGuidesDisable
+
+  for level in range(1, g:IndentGuides_indent_levels)
+    let group      = 'IndentLevel' . ((level % 2 == 0) ? 'Even' : 'Odd')
+    let multiplier = (&l:expandtab == 1) ? &l:shiftwidth : 1
+    let pattern    = '^\s\{' . (level * multiplier - multiplier) . '\}\zs'
+    let pattern   .= '\s\{' . multiplier . '\}'
+    let pattern   .= '\ze'
+
+    call add(g:IndentGuides_matches, matchadd(group, pattern))
+
+    if g:IndentGuides_debug
+      echo "matchadd ('" . group . "', '" . pattern . "')"
+    end
+  endfor
+endfunction
+
+function! s:IndentGuidesDisable()
+  if !empty(g:IndentGuides_matches)
+    let index = 0
+    for item in g:IndentGuides_matches
+      call matchdelete(item)
+      call remove(g:IndentGuides_matches, index)
+      let index += index
+    endfor
+  endif
+endfunction
+
+" Commands
+command! IndentGuidesToggle  call s:IndentGuidesToggle()
+command! IndentGuidesEnable  call s:IndentGuidesEnable()
+command! IndentGuidesDisable call s:IndentGuidesDisable()
+
+" Default options
+let g:IndentGuides_indent_levels = 50
+let g:IndentGuides_debug         = 0
+
+" Default highlight colors
+hi IndentLevelOdd  guibg=#252525
+hi IndentLevelEven guibg=#303030
+
+" Default mapping
+nmap <Leader>ig :IndentGuidesToggle<CR>
+