Build a POC showing how to use {context} in section IDs without changing existing URL fragments

The {context} variable needs to be added to every section ID in order to preserve unique IDs when an .adoc file is included multiple times.

On the other hand, adding the context variable to existing upstream documentation content must not affect existing URLs (including the fragment after #).

For example in blog/vaccination.adoc, a section with the following ID:

[id="vaccination-scheduler"]

will have URL: http://optaplanner.org/blog/vaccination.html#vaccination-scheduler

The goal is to "enrich" the AsciiDoc sources like this:

[id="vaccination-scheduler{context}"]

without affecting the URL (so it must stay http://optaplanner.org/blog/vaccination.html#vaccination-scheduler).