Add HTML patterns to be loaded by oik-patterns

[bobbingwide]

The oik-patterns plugin contains generic logic to load patterns from any installed theme that delivers patterns as .html files in the theme's patterns folder.

Patterns found in subdirectories are automatically associated with pattern categories.
eg patterns for Buttons would go in the patterns/buttons folder and those for Rows in the patterns/rows folder.

See bobbingwide/oik-patterns#2

Requirement

• Add patterns to be automatically processed by oik-patterns
• Patterns to be internationalized in the same / similar way as templates and template parts

Proposed solution

• Add a new pattern each time we think it's worthwhile.

[bobbingwide]

Also, add .json files for each pattern's .html file where we want to be able to use those patterns as page templates for add new.

[bobbingwide]

delivered in v1.2.0