automagically chop whitespace at the end of lines on save

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
add vim-slim plugin for slim templates

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
enable modelines

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>
set proper indentation on markdown files

Signed-off-by: Tyler Pickett <t.pickett66@gmail.com>