nix: add dev-shell (#944)

* nix: add dev-shell

* docs: add Nix dev shell in contributing docs

.gitignore

@@ -102,39 +102,6 @@ go.work.sum
 # .idea/
 # .vscode/
 
-# If you prefer the allow list template instead of the deny list, see community template:
-# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
-#
-# Binaries for programs and plugins
-*.exe
-*.exe~
-*.dll
-*.so
-*.dylib
-
-# Test binary, built with `go test -c`
-*.test
-
-# Code coverage profiles and other test artifacts
-*.out
-coverage.*
-*.coverprofile
-profile.cov
-
-# Dependency directories (remove the comment below to include it)
-# vendor/
-
-# Go workspace file
-go.work
-go.work.sum
-
-# env file
-.env
-
-# Editor/IDE
-# .idea/
-# .vscode/
-
 bin/
 
 # Extracted source trees in Ubuntu package directories  
@@ -142,3 +109,7 @@ distro/ubuntu/*/dms-git-repo/
 distro/ubuntu/*/DankMaterialShell-*/
 distro/ubuntu/danklinux/*/dsearch-*/
 distro/ubuntu/danklinux/*/dgop-*/
+
+# direnv
+.envrc
+.direnv/