updated readme for first release

README.md
added a small description about my contribution and requesting feedback
added description and usage of class methods #is_searchable? and alias: #searchable?
added description and usage of class_methods #searchable_by and alias: #findable_by
added description and usage of class methods #find_by_value and alias #search_for
added description and usage of instance methods #find_by_value and alias #search_for
demonstrated a walkthrough of how to install and use the gem
added prose embracing TDD
added a picture of test results

squashing
Merge pull request #15 from zachmokahn/05-updating_reading_for_beta_release

updated readme for first release