Add usage example to README.md

[avesanen]

Added a complete usage example to README.md.

[avesanen]

Included the complete program to the example, and pushed to develpment. Hopefully this is ok.

[coveralls]

Coverage increased (+4.08%) to 95.918% when pulling 587e810 on avesanen:develop into 0ba5e90 on epazote:develop.

[codecov-io]

Current coverage is 94.28% (diff: 100%)

Merging #3 into develop will not change coverage

@@            develop         #3   diff @@
==========================================
  Files             1          1          
  Lines            35         35          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
  Hits             33         33          
  Misses            1          1          
  Partials          1          1          

Powered by Codecov. Last update 0ba5e90...df7d6b2

[coveralls]

Coverage increased (+4.08%) to 95.918% when pulling df7d6b2 on avesanen:develop into 0ba5e90 on epazote:develop.

[coveralls]

Coverage increased (+4.08%) to 95.918% when pulling df7d6b2 on avesanen:develop into 0ba5e90 on epazote:develop.

[nbari]

Many thanks 💯