Many playgrounds on the pages doc site don't work, have bad fromatting

[mrjf]

make sure we have tests for th eplayground area

many don't run at all, some are formatted in a single row instead of 3x row

Need to 100% standardize them on the functional playgrounds that work, without the need to run bun and all that.

works: https://githubnext.github.io/tsessebe/diff_shift.html

doesn't work: https://githubnext.github.io/tsessebe/timedelta_range.html

Can we make a playwright test suite for this? And enforce that any new thing is not complete until it is playground-able and playwright tested.

[mrjf]

@copilot https://githubnext.github.io/tsessebe/infer_objects.html No playgrounds here.