Improve README: Add sort_link examples and a 2nd
Improve README: Add sort_link examples and a 2nd

controller code example, use f.search_field instead of f.text_field,
and clean up code formatting for readability

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nagyt234/ransack,roman-franko/ransack,vaski/ransack,mariorcardoso/ransack,reinteractive/ransack,martndemus/ransack,johan--/ransack,Eric-Guo/ransack,avit/ransack,laserlemon/ransack,outstand/ransack,AndrewSwerlick/ransack,guilleva/ransack,amboxer21/ransack,Mario245/ransack,activerecord-hackery/ransack