~/.vimrc: include rust vim files

.vimrc

	let g:goyo_callbacks = [function('s:goyo_before'), function('s:goyo_after')]
endif
if isdirectory($HOME . '/t/rust/src/etc/vim')
	set runtimepath+=~/t/rust/src/etc/vim
endif
" Have syntax highlighting and non-vi features
syntax on
filetype plugin indent on