docs: add jq howto

Covers navigation, filtering, transformation, string ops,
object manipulation, @format strings, and practical recipes.

TODO.md

@@ -5,7 +5,7 @@
 - [ ] git — common workflows, rebase, stash, bisect
 - [x] ansible — playbook patterns, inventory, vault, variables, roles
 - [ ] podman — build, run, compose, volumes
-- [ ] jq — filters, select, map, slurp
+- [x] jq — filters, select, map, slurp, recipes, @format
 - [ ] curl — headers, auth, methods, output
 - [ ] systemd — units, journalctl, timers
 - [ ] ssh — config, tunnels, keys, agent