Installation directions for people who don't have vundle

[Bhupesh-V]

Firstly thanks for the plugin 👍🏽

It would be nice to add installation directions for users who don't have vundle.
Plus it would be nice for new users to configure the setup easily, not everyone used vundle, plug etc

For e.g for neovim users :

1. Create the following path inside your nvim config folder & cd into it

   mkdir -p ~/.config/nvim/pack/vim-auto-save/start && cd $_

2. Clone vim-auto-save

    git clone https://github.com/907th/vim-auto-save.git

3. Change config in your init.vim file if needed and it is done!

Other methods

Let me know if this is what you want, I will send a PR

[xukongwen]

how about vim?