nix: allow dev setup via direnv

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -73,3 +73,6 @@ s3proxy-ca.crt
 
 # Lychee link checker
 .lycheecache
+
+# direnv
+.direnv

bazel/ci/shellcheck.sh.in

@@ -25,6 +25,7 @@ readarray -t <<< "${scriptsStr}"
 scripts=("${MAPFILE[@]}")
 
 excludeDirs=(
+  ".direnv"
   "internal/constellation/helm/charts/cilium"
   "build"
   "docs/node_modules"

dev-docs/workflows/build-develop-deploy.md

@@ -15,13 +15,22 @@ Prerequisites:
 
 ### Linux
 
-* If you don't want to perform any setup, you can get a shell with Bazel and all required dependencies by running:
+If you don't want to perform any setup, you can get a shell with Bazel and all required dependencies by running:
 
-  ```sh
-  # better would be: nix develop -i
-  # but this doesn't play nice with bashrc, colored output and non-hermetic tools
-  nix develop
-  ```
+```sh
+# better would be: nix develop -i
+# but this doesn't play nice with bashrc, colored output and non-hermetic tools
+nix develop
+```
+
+Or activate [direnv](https://direnv.net/) to automatically enter the nix shell.
+It is recommended to use [nix-direnv](https://github.com/nix-community/nix-direnv).
+If your system ships outdated bash, [install direnv](https://direnv.net/docs/installation.html) via package manager.
+Additionally, you may want to add the [vscode extension](https://github.com/direnv/direnv-vscode).
+
+```sh
+direnv allow
+```
 
 ### Mac