Migrating from slog-configurator

This module was github.com/psyb0t/slog-configurator through v1.5.0. Those versions keep resolving under the old path, so nothing breaks until you move. The CHANGELOG has the full story of each release.

Import paths

Before	After
`_ "github.com/psyb0t/slog-configurator"`	`_ "github.com/psyb0t/slogging/slogconf"`
`slogconfigurator.Init(...)`	`slogconf.Init(...)`
`github.com/psyb0t/slog-configurator/logring`	`github.com/psyb0t/slogging/handlers/logring`
`github.com/psyb0t/common-go/slogging/loki`	`github.com/psyb0t/slogging/handlers/loki`

Every exported name was unchanged in that move. Only import paths and the package name changed, so it was a find-and-replace on imports.

The handler API since v1.7.0

Before	After
`slogconf.AddHandler(sink)`	`slogconf.AddSink(sink)`
none	`slogconf.SetOutput(h)`, which swaps where you print and keeps the sinks
`slogconf.NewMultiWriterHandler(fmt, opts, out, err)`	`handlers.New(handlers.Options{...}, handlers.Stdout(out), handlers.Stderr(err))`
`slogconf.MultiWriterHandler`	`handlers.Handler`
`slogconf.FanOutHandler` / `NewFanOutHandler`	`handlers.FanOutHandler` / `handlers.NewFanOut`

MultiWriterHandler never was one. It took exactly two writers and routed between them by level. handlers.Handler is that thing named for what it does, and handlers.Stdout and handlers.Stderr are variadic, so several writers per stream is now something the API offers. See Output and fan-out handlers.

The Loki handler also dropped its gonfiguration and common-go dependencies. NewClient and NewHandler read the same SLOGGING_LOKI_URL and SLOGGING_LOKI_APPNAME variables as before, through the standard library.