feat: add initial nix development shell

This change bootstraps the configuration of a development shell via nix.

Change-Id: Ic171e7599b50bb29ecc07d9c4534bcbc117f2299

1 files changed, 99 insertions, 0 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 00000000..e929d672
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,99 @@
+# Contributing
+
+:wave: Hey there! Thanks for considering taking the time to contribute to
+`git-bug`. This page contains some general guidelines, and instructions for
+getting started as a contributor to this project.
+
+## Get the source code
+
+Clone this repository to your system in a way you're comfortable with. Below, we
+show a command that [clones the repository][how-to-clone] using SSH, and places
+it in `~/code/git-bug`.
+
+```
+git clone git@github.com:MichaelMure/git-bug ~/code/git-bug
+```
+
+> [!IMPORTANT]
+> If you wish to clone the repository to another location on disk, change
+> `~/code/git-bug` to your desired path. The rest of this documentation will
+> refer to `~/code/git-bug` in all instances, so make sure you change them
+> there, too.
+
+## Software recommendations
+
+While you can install Golang and hack on this project on your own, you're likely
+to have a better experience if you install the following software.
+
+### <a name="install-nix"></a> `nix` (_recommended_)
+
+[`nix`][install/nix] is used in this repository to provide a common development
+shell, with a complete set of the appropriate version of the tools used to work
+on `git-bug`.
+
+You can install `nix` by following [the official instructions][install/nix], but
+we recommend adding some additional flags in order to enable some (technically
+experimental, but largely stable) configuration options:
+
+```
+curl -L https://nixos.org/nix/install | sh -s -- --daemon --nix-extra-conf-file <( \
+cat << EOF | sed -e 's/^ *//'
+  experimental-features = nix-command flakes
+EOF
+)
+```
+
+> [!TIP]
+> Make sure you read the prompts from the installation script carefully. After
+> installation, you'll need to start a new shell.
+
+### <a name="install-direnv"></a> `direnv` (_recommended_)
+
+[`direnv`][install/direnv] is used to automatically activate the development
+shell (because of the `.envrc` in the root of this repository).
+
+#### <a name="install-direnv-with-nix"></a> With `nix`
+
+> [!IMPORTANT]
+> If you are not comfortable with `nix`, we recommend [installing `direnv`
+> without nix][install/install-direnv-without-nix].
+
+```
+nix --extra-experimental-options 'flakes nix-command' profile install nixpkgs\#direnv
+```
+
+There's a second step that is critical -- be sure to [configure your
+shell][install/direnv/shell].
+
+#### <a name="install-direnv-without-nix"></a> Without `nix`
+
+You can install `direnv` by following [the official
+instructions][install/direnv]. There's a second step that is critical -- be sure
+to [configure your shell][install/direnv/shell].
+
+After installation, you'll need to start a new shell.
+
+##### <a name="direnv-config"></a> direnv configuration (_recommended_)
+
+If you install `direnv`, it is recommended to set the following configuration
+options to improve your user experience. At the time of writing, these go in
+`~/.config/direnv/direnv.toml`.
+
+This configuration, namely, the `whitelist.exact` property, will ensure that
+`direnv` always automatically sources the `.envrc` in this repository.
+
+```
+hide_env_diff = true
+warn_timeout = 0
+
+[whitelist]
+exact = ["~/code/git-bug/.envrc"]
+```
+
+> [!IMPORTANT]
+> Make sure you change the `~/code/git-bug` portion of the string to the
+> appropriate path (the path that you cloned this repository to on your system).
+
+[install/nix]: https://nix.dev/install-nix
+[install/direnv]: https://github.com/direnv/direnv/blob/master/docs/installation.md
+[install/direnv/shell]: https://github.com/direnv/direnv/blob/master/docs/hook.md