Update airline documentation

+ Update README and linked image

Author: jcbwlkr

.vimrc

@@ -751,11 +751,19 @@
         let g:indent_guides_enable_on_vim_startup = 1
     " }
 
-    " airline {
-        let g:airline_theme='powerlineish'      " airline users use the powerline theme
+    " vim-airline {
+        " Set configuration options for the statusline plugin vim-airline.
+        " Use the powerline theme and optionally enable powerline symbols.
+        " To use the symbols , , , , , , and .in the statusline
+        " segments add the following to your .vimrc.before.local file:
+        "   let g:airline_powerline_fonts=1
+        " If the previous symbols do not render for you then install a
+        " powerline enabled font.
+        let g:airline_theme = 'powerlineish'
         if !exists('g:airline_powerline_fonts')
-            let g:airline_left_sep='›'          " Slightly fancier separator, instead of '>'
-            let g:airline_right_sep='‹'         " Slightly fancier separator, instead of '<'
+            " Use the default set of separators with a few customizations
+            let g:airline_left_sep='›'  " Slightly fancier than '>'
+            let g:airline_right_sep='‹' " Slightly fancier than '<'
         endif
     " }
 

README.markdown

@@ -398,7 +398,7 @@ For example this screen shot demonstrates pressing `,,w`
 
 ## [Airline]
 
-Airline provides a lightweight themable statusline with no external dependencies. By default it uses the symbols `‹` and `›` as separators for different statusline sections but can be configured to use the same symbols as [Powerline]. An example with and without powerline symbols is shown here:
+Airline provides a lightweight themable statusline with no external dependencies. By default this configuration uses the symbols `‹` and `›` as separators for different statusline sections but can be configured to use the same symbols as [Powerline]. An example first without and then with powerline symbols is shown here:
 
 ![airline image][airline-img]
 
@@ -500,4 +500,4 @@ Here's some tips if you've never used VIM before:
 [nerdtree-img]:https://i.imgur.com/9xIfu.png
 [phpmanual-img]:https://i.imgur.com/c0GGP.png
 [easymotion-img]:https://i.imgur.com/ZsrVL.png
-[airline-img]:https://i.imgur.com/sU0PG5P.png
+[airline-img]:https://i.imgur.com/D4ZYADr.png