Add support for CSAF field

[tschmidtb51]

fixes #92

[EdOverflow]

Thank you for the pull request, @tschmidtb51. This looks good to me but I will wait for @joker314 to review this if they get a chance just to make sure.

[joker314]

Will review later today, but it looks good

[joker314]

The changes to the YAML are correct and look good. 👍 Thank you for submitting it.

The way the form currently works is that the field names have to be listed once more in the JavaScript in order for them to be included in the output.

securitytxt.org/js/genform.js

Lines 27 to 29 in 615a74f

	generate('security.txt', [
	"contact", "expires", "encryption", "acknowledgments", "preferredLanguages", "canonical", "policy", "hiring"
	]);

However, the existing code converts camel case into hyphens, but we don't want that here (it would lead to C-S-A-F: instead of CSAF:). In the short term we could special-case the CSAF field, but I think it would be better to update the JS so this problem does not occur in the future. I will make that update in the next few days, and then we can merge this PR.

[tschmidtb51]

@joker314 Sorry for the long radio silence. I added the id csaf to be included in the output.

[tschmidtb51]

@joker314 I created #95 as replacement if you want the short term hack.