[phb][security]: Create VuXML checklist

[fernape]

Summary

Create a short checklist with some important points to check before committing.
Prompted by a mail by mandree@.

Test Plan

Apply patch, make run in the documentation/ directory and go to localhost:1313 to inspect the result.

[bcr]

A few minor textual suggestions.

documentation/content/en/books/porters-handbook/security/_index.adoc

326

How about active voice here:
Use the following script to generate ...

335

s/can help/helps/

347

s/instance package:/instance, package:/

[fernape]

Address bcr@ feedback

[bcr]

Looks good now, thank you!

[fernape]

Thanks for the review!