Add support for Fortran

[ZedThree]

Should work for most standard versions of Fortran, from 77 to 2008. Doesn't work so well for fixed-form source, e.g. "C" in the first column for comments.

Also, not sure how to generate the "correct" annotated output for the test case. Is there a tool in the repo?

[amroamroamro]

there was also a lang-fortran.js proposed a few years ago: #78 (comment), just in case you want to compare against it and maybe even merge the two if there is a need...

[ZedThree]

Thanks, looking at that helped me work out how to fix Fortran77 style comments!

[ZedThree]

Hello, what do I need do to get this moving? I'd really like to get this merged so stackoverflow can use it :)

[YodaEmbedding]

Bump

[xinye83]

Hey, thank you for making this! Three changes you can consider making to make it more robust.

1. Add "end" keyword to "PR_KEYWORD".
2. Add "logical" keyword to "PR_TYPE".
3. If the first line is a comment, it won't be properly shown as a comment in the browser.

[noloader]

Bump...