add Screenshots section with description and links

previous content named Installation

README.md

@@ -1,20 +1,47 @@
 Lupan's config files
 ====================
 
-To reproduce my environment clone this repo into `~/dotfiles` check
+Screenshots
-that you have required programs in your PATH with
+-----------
+
+Short answer: [screenshots here](https://lupan.pl/lupan-themes/).
+
+My configuration allows to switch between my 6 themes using a shell
+script bound to a key stroke (`super + F6` for switching themes in a
+cycle and `super + shift + F6` for selecting one with `dmenu`).  The
+theme is applied to *bspwm*, *Polybar*, *Alacritty*, *Emacs*, and
+*Gtk3* (with support for reloading themes in active *Gtk3*
+applications, but I currently use only two *Gtk3* themes: one dark and
+one light).
+
+You can see the screenshots of my whole workspace with each of the
+themes applied on the page describing [my Emacs
+themes](https://lupan.pl/lupan-themes/).  For the Emacs theme
+reloading I use simple helper Emacs function `my-select-theme`
+available from [Toggle between dark and light themes with a
+key](https://lupan.pl/dotemacs/#toggle-between-dark-and-light-themes-with-a-key)
+section of my Emacs config (also available in corresponding [GitHub
+repo](https://github.com/lukpank/.emacs.d).
+
+
+Installation
+------------
+
+To reproduce my environment clone this repo into `~/dotfiles` and check
+that you have required programs in your `PATH` with
 
 ```
 $ sh check_dependencies.sh
 ```
 
-and run
+Then run
 
 ```
 $ stow -v alacritty bspwm music shell tmux
 ```
 
-if you want i3 instead of bspwm (left as a fallback) *also* run
+but if you want *i3* config (left as a fallback) instead of *bspwm*
+then *also* run
 
 ```
 $ stow -v i3