Breaking changes for setLiquidOptions in 1.0

[zachleat]

Because the major version of Liquid changed, there might be breaking changes here for those using setLiquidOptions. Specifically:

+1 to shimming "strict_filters" to "strictFilters" when bumping up to liquidjs v9 (so that both are supported and we don't break anything).

via @pdehaan in #469 (comment)

(note that we have strict_filters examples in the docs too)

I’m leaning towards not shimming these per the 1.0 release—but we should at least add a console warning and list them in the migration guide (and update the docs too).

[zachleat]

Further complicating this, we changed the default value too for 1.0: #222

[zachleat]

Code merged for this into the https://github.com/11ty/eleventy-upgrade-help plugin

[zachleat]

Docs updated.