feat(nix): replace devenv with flake; cleanups

.cargo/config.toml

@@ -10,3 +10,6 @@ time = "run --quiet --release -- time"
 
 [env]
 AOC_YEAR = "2023"
+
+[target.x86_64-unknown-linux-gnu]
+linker = "clang"

.editorconfig

@@ -2,10 +2,10 @@
 root = true
 
 [*]
+charset = utf-8
+end_of_line = lf
 indent_size = 4
 indent_style = space
-end_of_line = lf
-charset = utf-8
 insert_final_newline = true
 trim_trailing_whitespace = true
 
@@ -15,3 +15,6 @@ trim_trailing_whitespace = false
 
 [*.md]
 trim_trailing_whitespace = false
+
+[*.nix]
+indent_size = 2

.envrc

@@ -1,3 +1,7 @@
-source_url "https://raw.githubusercontent.com/cachix/devenv/95f329d49a8a5289d31e0982652f7058a189bfca/direnvrc" "sha256-d+8cBpDfDBj41inrADaJt+bDWhOktwslgoP5YiGJ1v0="
+#! /usr/bin/env bash
 
-use devenv
+watch_file \
+    nix/modules/*.nix \
+    nix/lib.nix
+
+use flake

.gitignore

@@ -1,20 +1,22 @@
-# Generated by Cargo
-# will have compiled files and executables
+## Nix
+.direnv*
+.pre-commit-config.yaml
+
+## Rust
+# compiled files and executables
 debug/
 target/
 
-# These are backup files generated by rustfmt
+# backup files generated by rustfmt
 **/*.rs.bk
 
 # MSVC Windows builds of rustc generate these, which store debugging information
 *.pdb
 
+# Tools
+.bacon-locations
 
-# Added by cargo
-
-/target
-
-# Advent of Code
+## Advent of Code
 # @see https://old.reddit.com/r/adventofcode/comments/k99rod/sharing_input_data_were_we_requested_not_to/gf2ukkf/?context=3
 
 data/inputs/*
@@ -26,15 +28,4 @@ data/puzzles/*
 dhat-heap.json
 
 # Benchmarks
-
 data/timings.json
-
-# Nix
-.devenv*
-.direnv*
-
-# Tools
-.bacon-locations
-
-# pre-commit
-.pre-commit-config.yaml