Improve vim by installing vundle package manager, following plugins and using keyboard shortcuts

.vimrc

" Steps
" =====
" 1. Add below content to your .vimrc
" 2. Clone vundle : `git clone https://github.com/VundleVim/Vundle.vim.git ~/.vim/bundle/Vundle.vim`
" 3. Run :PluginInstall in vim


" --------------------------------------------------
" Vundle package manager settings
" --------------------------------------------------
set nocompatible
filetype off

" ---------- Set path of vundle file ----------
set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()
Plugin 'VundleVim/Vundle.vim'

" ---------- Plugins list start ----------

" -- File explorer --
Plugin 'scrooloose/nerdtree'
Plugin 'jistr/vim-nerdtree-tabs'

" -- Bracket matching --
"Plugin 'tpope/vim-surround'

" -- Autocompletion --
Plugin 'mattn/emmet-vim'
"Plugin 'Valloric/YouCompleteMe'
"Plugin 'SirVer/ultisnips'
"Plugin 'davidhalter/jedi-vim'

" -- Line numbers & indentation --
"Plugin 'Yggdroot/indentLine'

" -- Comments --
"Plugin 'tomtom/tcomment_vim'

" -- Git support --
"Plugin 'airblade/vim-gitgutter'

" -- Color scheme --
Plugin 'flazz/vim-colorschemes'

" -- Language specific syntax and completion --
" Plugin 'pangloss/vim-javascript'

" -- Other plugins --
"Plugin 'kien/ctrlp.vim'

" ---------- Plugins list end ----------

" All of your Plugins must be added before the following line
call vundle#end()
filetype plugin indent on
" To ignore plugin indent changes, instead use:
"filetype plugin on
" ---------- Vundle help ----------
" Brief help
" :PluginList       - lists configured plugins
" :PluginInstall    - installs plugins; append `!` to update or just :PluginUpdate
" :PluginSearch foo - searches for foo; append `!` to refresh local cache
" :PluginClean      - confirms removal of unused plugins; append `!` to auto-approve removal
"
" see :h vundle for more details or wiki for FAQ
" Put your non-Plugin stuff after this line



" --------------------------------------------------
" Color scheme settings
" --------------------------------------------------
syntax enable
let g:rehash256 = 1

" Below scheme is included in flazz/vim-colorschemes plugin
colorscheme Monokai
" Following colorschemes need to be downloaded from github (username is mentioned):
"colorscheme monokai_crusoexia
"colorscheme monokai_jaromero
"colorscheme monokai_sickill
"colorscheme molokai_tomasr
" If tomasr/molokai theme is used, uncomment the following line
"let g:molokai_original = 1



" --------------------------------------------------
" Functions
" --------------------------------------------------
" Switch between line number mode
function! NumberToggle()
	if(&number == 0 && &relativenumber == 0)
		set number
		set relativenumber
	elseif(&relativenumber == 1)
		set norelativenumber
		set number
	else
		set nonumber
	endif
endfunc



" --------------------------------------------------
" Settings for runtime initialisation
" --------------------------------------------------
set tabstop=4 shiftwidth=4
call NumberToggle()



" --------------------------------------------------
" Keyboard mappings
" --------------------------------------------------
" Move line up/down with Ctrl+Shift+Up/Down (just like Sublime Text)
nnoremap <C-S-Up> :m-2<CR>
nnoremap <C-S-Down> :m+1<CR>
" Change width of file explorer/editor area (when both are opened)
nnoremap <C-S-Left> :vertical resize -1<CR>
nnoremap <C-S-Right> :vertical resize +1<CR>
" Toggle line numbers using NumberToggle functions (defined above)
nnoremap <C-l> :call NumberToggle()<cr>
" Find
nnoremap <C-f> /
inoremap <C-f> <Esc>/


" --------------------------------------------------
" Plugins settings & mappings
" --------------------------------------------------

" NERDTree
nnoremap <S-n> :NERDTreeToggle<CR>