Update Variability Function: random_word_image

[a8081]

It would be interesting to be able to configure lower/upper case and to specify when we want the font size to fill all the crop we indicate to the function

[a8081]

Another idea it would be to be able to generate words specifying a bag of words, for example:

• Countries (indicating the continent)
• Cities (indicating the country)
• Names
• Surnames
• Streets
• Zip codes
• emails
• id card number...