Document g:onehalf_italic

Author: jawang35

vim/README.md

@@ -21,15 +21,17 @@ Download the files in [vim/](./) and put them in their respective folders
 ## Usage
 Put `colorscheme <scheme>` and `let g:airline_theme='<theme>'`, if using airline
 or `let g:lightline = { 'colorscheme': '<theme>' }`, if using lightline, in your `.vimrc`
-to set the color scheme and airline (or lightline) theme. Make sure you have
-syntax highlighting on, and 256 colors set. Vim version >= 7.4 recommended.
+to set the color scheme and airline (or lightline) theme. `let g:onehalf_italic = 1`
+before `colorscheme` to enable italics (requires terminal and font support). Make sure
+you have syntax highlighting on, and 256 colors set. Vim version >= 7.4 recommended.
 
 For example:
 
 ```
 syntax on
 set t_Co=256
 set cursorline
+let g:onehalf_italic = 1
 colorscheme onehalflight
 let g:airline_theme='onehalfdark'
 " lightline