build: Replace `make config` with a `./configure` script

This lets us do more traditional out-of-tree builds like

    $ ../path/to/bfs/configure
    $ make

The .mk files are moved from ./config to ./build, mostly so that
./configure will auto-complete easily.

1 files changed, 0 insertions, 6 deletions

diff --git a/config/empty.c b/config/empty.c
deleted file mode 100644
index 4fa9a5b..0000000
--- a/config/empty.c
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright © Tavian Barnes <tavianator@tavianator.com>
-// SPDX-License-Identifier: 0BSD
-
-int main(void) {
-	return 0;
-}