Update documentation and fix bugs

[rohitharavinder]

The hybrid-pre-doc2vec-doc-relevance had an incomplete documentation before @endri16-lab started the re-run.
Things to be fixed were mentioned by @Soudeh-Jahanshahi as part of this issue.

• Modify README
• Fix bugs
  • 1. Function to load numpy file
  • 2. Cosine similarity function returns empty relevance matrix
  • 3. Add evaluation scripts to the repo

[ljgarcia]

@Soudeh-Jahanshahi before I fully close this issue, could you please let me know if you are happy with the modifications? They come from come issues that you raised. Thanks

[Soudeh-Jahanshahi]

@ljgarcia : Please consider this issue for more detailed report. Briefly to say everything works well and the documentation is very clear to understand and follow ...