docs: update contributing guide to reflect changes in workflows

Author: shenxianpeng

CONTRIBUTING.md

@@ -4,6 +4,7 @@ This project requires the following tools installed:
 
 - :simple-rust: [rust](https://rustup.rs/)
 - :simple-uv: [`uv` (Python Project management tool)](https://docs.astral.sh/uv/)
+- :simple-nushell: [nushell](https://www.nushell.sh/) (for running tasks via `nur`)
 
 ## Getting started
 
@@ -14,7 +15,7 @@ uv sync
 ```
 
 This creates a venv at ".venv/" in repo root (if it doesn't exist).
-It also installs dev dependencies like `pre-commit`, `nox`, `ruff`, and `mypy`.
+It also installs dev dependencies like `pre-commit`, `ruff`, and `mypy`.
 
 See [`uv sync` docs](https://docs.astral.sh/uv/reference/cli/#uv-sync)
 for more detailed usage.
@@ -32,47 +33,45 @@ First ensure that the following cargo-managed binaries are installed:
 
 - [`cargo-llvm-cov`](https://github.com/taiki-e/cargo-llvm-cov)
 - [`cargo-nextest`](https://nexte.st/docs/installation/pre-built-binaries/)
-- [`llvm-cov-pretty`](https://crates.io/crates/llvm-cov-pretty) is used only for the optional `nox -s pretty-cov` task. Without this installed, `nox -s llvm-cov` will suffice.
-
-Use nox to run tests:
+Use `nur` to run tests:
 
 ```sh
-uv run nox -s test
+nur test
 ```
 
 Different test profiles are still defined in .config/nextest.toml.
 The above command uses the "default" profile, but to mimic the CI, use:
 
 ```sh
-uv run nox -s test -- --profile ci
+nur test --profile ci
 ```
 
 To generate a coverage report:
 
 ```sh
-uv run nox -s llvm-cov -- --open
+nur test llvm-cov --open
 ```
 
-The `-- --open` part is optional. It opens the built coverage report in your default browser.
+The `--open` flag is optional. It opens the built coverage report in your default browser.
 
 The uploaded codecov report is generated with
 
 ```sh
-uv run nox -s lcov
+nur test lcov
 ```
 
 ## Generating docs
 
 To view the docs locally, use
 
 ```sh
-uv run nox -s docs -- --open
+nur docs --open
 ```
 
-The `-- --open` part is optional. It opens the built docs in your default browser.
+The `--open` flag is optional. It opens the built docs in your default browser.
 
 In CI, docs are built using
 
 ```sh
-uv run nox -s docs-build
+nur docs --build
 ```