add topics

[Beliavsky]

I suggest adding the topics string, strings in the About section.

[szaghi]

@Beliavsky Thank you very much for your suggestions. I am in doubt, however: what do you mean with "About section" (readme, source doc, wiki...) and what do you suggest to write in these topics?

[Beliavsky]

You already list the topics parsing, oop, string-manipulation in the About section. I am suggesting some additional topics to list there, so that someone who searches topic:string language:fortran finds your repo.

[szaghi]

@Beliavsky sorry, I was totally out of the way :-)

You are right, I have to add those keywords.

Kind regards, Stefano