Inconsistent documentation and improvements

[dgarijo]

In https://somef.readthedocs.io/en/latest/output/ We have:

• Inconsistent use of types: Programming_language on the one hand and PROGRAMMING_LANGUAGE on the other (we should not use capital letters)
• In the types table, we should order them alphabetically
  Also add that the types are closely aligned to schema.org / CodeMeta

[dgarijo]

Also in role String role of agent -> Role of the agent in what? It's the role in the development of this software component.

[dgarijo]

Also, in citation: Software citation (usually in .bib form) as the authors have stated in their readme file, or through a CFF file.
we now extract the information of the citations, we don't just have a string with the citation info