Add devbox and pre-commit hook (#637)

To further improve developer experience, this PR adds the following:
- devbox for a common development environment
- pre-commit hooks for formatting

.gitattributes

@@ -0,0 +1,2 @@
+devbox.lock binary linguist-generated=true eol=lf
+

.pre-commit-config.yaml

@@ -0,0 +1,7 @@
+repos:
+-   repo: https://github.com/doublify/pre-commit-rust
+    rev: v1.0
+    hooks:
+    -   id: fmt
+    -   id: cargo-check
+

README.md

@@ -137,10 +137,41 @@ To build webrtc crate:
 cargo build [or clippy or test or fmt]
 ```
 
+### Devbox
+
+This repo now supports [devbox](https://www.jetify.com/devspace) for a better development experience.
+In short, devbox allows to define a development environment by modifying the `PATH` variable in your shell.
+It is based on nix and runs on Linux, MacOS, and WSL.
+To use devbox, install it from [devbox installation](https://www.jetify.com/docs/devbox/installing_devbox/):
+
+```bash
+curl -fsSL https://get.jetify.com/devbox | bash
+```
+
+Now you can either use the different devbox scripts:
+
+- test it: `devbox run test`
+- build it: `devbox run build`
+- format it: `devbux run format`
+
+Or you can enter a shell with everything pre-installed:
+
+```bash
+devbox shell
+```
+
 ## Open Source License
 
 Dual licensing under both MIT and Apache-2.0 is the currently accepted standard by the Rust language community and has been used for both the compiler and many public libraries since (see <https://doc.rust-lang.org/1.6.0/complement-project-faq.html#why-dual-mitasl2-license>). In order to match the community standards, webrtc-rs is using the dual MIT+Apache-2.0 license.
 
 ## Contributing
 
 Contributors or Pull Requests are Welcome!!!
+
+If you want to contribute, please be sure to install the pre-commit hooks:
+
+```bash
+pre-commit install
+```
+
+Or use the devbox environment described above, which will do so automatically.

devbox.json

@@ -0,0 +1,41 @@
+{
+  "$schema": "https://raw.githubusercontent.com/jetify-com/devbox/0.10.7/.schema/devbox.schema.json",
+  "packages": {
+    "git":        "latest",
+    "pre-commit": "latest",
+    "rustup":     "latest",
+    "libiconv":   "latest",
+    "darwin.apple_sdk.frameworks.SystemConfiguration": {
+      "platforms": ["x86_64-darwin", "aarch64-darwin"],
+    },
+    "darwin.apple_sdk.frameworks.Security": {
+      "platforms": ["x86_64-darwin", "aarch64-darwin"],
+    },
+    "darwin.apple_sdk.frameworks.CoreServices": {
+      "platforms": ["x86_64-darwin", "aarch64-darwin"],
+    },
+    "vim":  "latest",
+    "less": "latest",
+    "openssh": "latest",
+  },
+  "shell": {
+    "init_hook": [
+      "pre-commit install",
+      "if [ ! -d $RUSTUP_HOME/toolchains/stable* ]; then rustup default stable; fi",
+    ],
+    "scripts": {
+      "test": [
+        "cargo test",
+      ],
+      "build": [
+        "cargo build",
+      ],
+      "fmt": [
+        "cargo fmt",
+      ],
+    },
+  },
+  "env": {
+    "LS_COLORS": "di=33",
+  },
+}