"Unhide" the Ruff config directory

There's no point in introducing a new dot directory.

MANIFEST.in

-recursive-include .config *.toml
+recursive-include config *.toml
 include .editorconfig
 include CHANGELOG.md
 recursive-include nix *.nix *.sh

pyproject.toml

@@ -71,7 +71,7 @@ load-plugins = [
 ]
 
 [tool.ruff]
-extend = ".config/ruff-base/pyproject.toml"
+extend = "config/ruff-base/pyproject.toml"
 select = ["E", "F"]
 
 [tool.test-stages]

tox.ini

@@ -32,7 +32,7 @@ tags =
 deps =
   ruff == 0.0.241
 commands =
-  ruff check --config .config/ruff-all/pyproject.toml -- {[defs]pyfiles}
+  ruff check --config config/ruff-all/pyproject.toml -- {[defs]pyfiles}
 
 [testenv:black]
 skip_install = True