added 'jquery', 'underscore' files and implemented 'global.css', 'index.html' and 'repeated_words.js'
implemented main files (2)
implemented function 'escapeHtml' in 'repeated_words.js' file
added 'prueba3.txt' file and implemented function 'generateOutput' in 'repeated_words.js' file
added 'README.md' file and modified regular expressions in 'repeated_words.js'