Add installation instructions for vim 8+

Vim 8+ supports installing plugins using the Vim's plugin manager.
By creating .vim/pack/<plugin-directory>/start directory and cloning
the plugin directory there. It will be loaded at startup no need to
load it automatic or to add any configuration in the .vimrc
configuration file.

Author: namestarlit

README.md

@@ -12,14 +12,17 @@
 
 1. With [Vundle](https://github.com/gmarik/vundle): `echo "Plugin 'wakatime/vim-wakatime'" >> ~/.vimrc && vim +PluginInstall`
 
-   Or with [Pathogen](https://github.com/tpope/vim-pathogen): `cd ~/.vim/bundle && git clone git://github.com/wakatime/vim-wakatime.git`
+   Or with [Pathogen](https://github.com/tpope/vim-pathogen): `cd ~/.vim/bundle && git clone https://github.com/wakatime/vim-wakatime.git`
 
    Or with [Vim-plug](https://github.com/junegunn/vim-plug):  add `Plug 'wakatime/vim-wakatime'` to .vimrc file. While in vim reload .vimrc with `:so ~/.vimrc` or restart vim, enter
     `:PlugInstall`
 
-   Or with [Packer](https://github.com/wbthomason/packer.nvim): add `use 'wakatime/vim-wakatime'` to your plugins file.
+   Or with [Packer](https://github.com/wbthomason/packer.nvim): add `use 'wakatime/vim-wakatime'` to your plugins file.  
+   Or with [Vim 8+](https://www.vim.org/): `mkdir -p ~/.vim/pack/plugins/start && ~/.vim/pack/plugins/start && git clone https://github.com/wakatime/vim-wakatime.git`
 
-2. Enter your [api key](https://wakatime.com/settings#apikey), then press `enter`.
+   Then start `vim`. You should be prompted to enter your WakaTime [API Key](https://wakatime.com/settings#apikey).
+
+2. Enter your [API Key](https://wakatime.com/settings#apikey), then press `enter`.
 
 3. Use Vim and your coding activity will be displayed on your [WakaTime dashboard](https://wakatime.com).