my super duper vim configuration for vim-plug

.vimrc

set nocompatible              " be iMproved, required
filetype off                  " required


syntax enable                               " syntax highlight

set t_Co=256                                " set 256 colors

set number                                  " show line numbers
set ruler
set ttyfast                                 " terminal acceleration

set tabstop=4                               " 4 whitespaces for tabs visual presentation
set shiftwidth=4                            " shift lines by 4 spaces
set smarttab                                " set tabs for a shifttabs logic
set expandtab                               " expand tabs into spaces
set autoindent                              " indent when moving to the next line while writing code

set showmatch                               " shows matching part of bracket pairs (), [], {}

set enc=utf-8	                            " utf-8 by default

set nobackup 	                            " no backup files
set nowritebackup                           " only in case you don't want a backup file while editing
set noswapfile 	                            " no swap files

set backspace=indent,eol,start              " backspace removes all (indents, EOLs, start) What is start?

set scrolloff=10                            " let 10 lines before/after cursor during scroll

set clipboard=unnamed                       " use system clipboard

set exrc                                    " enable usage of additional .vimrc files from working directory
set secure                                  " prohibit .vimrc files to execute shell, create files, etc...

au BufNewFile,BufRead *.py
    set tabstop=4
    set softtabstop=4
    set shiftwidth=4
    set textwidth=79
    set expandtab
    set autoindent
    set fileformat=unix


call plug#begin('~/.vim/plugged')
    Plug 'tpope/vim-fugitive'
    Plug 'bling/vim-airline'                  " Lean & mean status/tabline for vim
    Plug 'vim-airline/vim-airline-themes'     " Themes for airline
    Plug 'Valloric/YouCompleteMe', { 'do': './install.py --all' }
    Plug 'vim-syntastic/syntastic'
    Plug 'nvie/vim-flake8'
    Plug 'scrooloose/nerdtree'
    Plug 'jistr/vim-nerdtree-tabs'
    Plug 'ryanoasis/vim-devicons'
    Plug 'tiagofumo/vim-nerdtree-syntax-highlight'
    Plug 'kien/ctrlp.vim'
    Plug 'dense-analysis/ale'
    Plug 'davidhalter/jedi'
    Plug 'tpope/vim-commentary'
call plug#end()

let g:airline_theme='dark_minimal'
let g:airline#extensions#tabline#enabled=1
let g:airline#extensions#tabline#formatter='unique_tail'
let g:airline_powerline_fonts=1

let g:ycm_autoclose_preview_window_after_completion=1
map <leader>g  :YcmCompleter GoToDefinitionElseDeclaration<CR>

let python_highlight_all=1
syntax on

" Open the existing NERDTree on each new tab.
autocmd BufWinEnter * silent NERDTreeMirror

" Mirror the NERDTree before showing it. This makes it the same on all tabs.
nnoremap <C-n> :NERDTreeMirror<CR>:NERDTreeFocus<CR>

let g:NERDTreeDirArrowExpandable = '▸'
let g:NERDTreeDirArrowCollapsible = '▾'

let mapleader = ","

filetype plugin indent on    " required