update tests, too

upgrade stdlib

use Justfile

move build commands to Deno tasks

bump luxon

deno: bump stdlib

upgrade to Deno 1.28 and its new lock system

bump stdlib

use stricter type checking enforced in Deno 1.25

upgrade luxon

upgrade Deno stdlib

readme: add build status

deps: bump Deno stdlib to 0.145

In addition to mechnically going to the newest Deno stdlib, this also
updates the collections/ inclusions to follow contemporary best
practices, which avoid using the mod.ts.

Fixes: https://todo.sr.ht/~bmp/hayom/10

add deno.json for building dependencies

deps: bump Deno stdlib to 0.144

tests: typecheck

deps: bump Deno stdlib to 0.142

deps: bump Deno stdlib to 0.136

update dependencies and Deno version

readme: fix up community docs