Answerable v1.1

• Improve the recommendation model: add content_based_1 model and make it the default one.
• Enable user defined recommendation models: add -m MODEL --model MODEL option.
• Display additional information from the system: add -i --info option.
• Enable including questions not answered by the user, using the include.txt file.
• Automatically check for updates in the GitHub repository.
• Improve the warning and error messages.
• Minor bug fixes.