formatter: map -Tjson(...) and -Tcbor(...) to templater
Even though custom JSON output could be generated by using
--config template.json="{dict(...)|json}" ..., doing that is tedious because
of the trailing comma handling.
This patch introduces special syntax for JSON/CBOR formats. -Tjson(...) is
translated to template as if function-style template definition were
supported:
[templates]
json(...) = "{dict(...)|json}"
json(...):docheader = "[\n "
json(...):docfooter = "\n]\n"
json(...):separator = ",\n "
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}