Add finish local_storage example.

Author: robinheghan

Diff for: Makefile

@@ -3,7 +3,8 @@ common_examples := counter\
 			flight_booker\
 			hello_world\
 			temperature_converter\
-			timer
+			timer\
+			local_storage
 
 all_examples := $(common_examples) todo_mvc
 

Diff for: README.md

@@ -13,20 +13,27 @@ Traditionally the first program one creates in any language, here implemented as
 
 [7GUIs](https://eugenkiss.github.io/7guis) is a set of small tasks, suitable for demonstrating how common GUI patterns can be implemented in a specific framework. The following folders implement the solutions to the [7GUIs tasks](https://eugenkiss.github.io/7guis/tasks):
 
-* counter 
+* counter
     [code](https://github.com/gren-lang/example-projects/blob/main/counter/src/Main.gren) /
     [demo](https://htmlpreview.github.io/?https://github.com/gren-lang/example-projects/blob/main/counter/Example.html)
-* temperature\_converter 
+* temperature\_converter
     [code](https://github.com/gren-lang/example-projects/blob/main/temperature_converter/src/Main.gren) /
     [demo](https://htmlpreview.github.io/?https://github.com/gren-lang/example-projects/blob/main/temperature_converter/Example.html)
-* flight\_booker 
+* flight\_booker
     [code](https://github.com/gren-lang/example-projects/blob/main/flight_booker/src/Main.gren) /
     [demo](https://htmlpreview.github.io/?https://github.com/gren-lang/example-projects/blob/main/flight_booker/Example.html)
-* timer 
+* timer
     [code](https://github.com/gren-lang/example-projects/blob/main/timer/src/Main.gren) /
     [demo](https://htmlpreview.github.io/?https://github.com/gren-lang/example-projects/blob/main/timer/Example.html)
 * __more to come__
 
+## local\_storage
+
+[code](https://github.com/gren-lang/example-projects/blob/main/local_storage/src/Main.gren) /
+[demo](https://htmlpreview.github.io/?https://github.com/gren-lang/example-projects/blob/main/local_storage/Example.html)
+
+This program shows how you can make use of the `gren-lang/web-storage` package for storing values in local storage.
+
 ## files
 
 [code](https://github.com/gren-lang/example-projects/blob/main/files/src/Main.gren) /