docs: add project README; add demo image

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Id431ecf386999abb857c9b6dbde989216a6a6964

docs/README.md

@@ -0,0 +1,46 @@
+# nix-evaluator-stats
+
+A pretty visualiser for Nix evaluator stats from `NIX_SHOW_STATS` and
+`NIX_COUNT_CALLS` invocations.
+
+![Demo](./assets/ns-demo.png)
+
+ns takes the resulting JSON data from your Nix invocation with the relevant
+variables, and provides a ✨ pretty ✨ dashboard-like visual with the ability to
+compare your "snapshots" of benchmarks. Besides looking nice, it is helpful in
+collecting statistics about your Nix commands and tracking performance
+regressions in subsequent exports.
+
+## Usage
+
+Usage instructions are provided in the initial page. Simply navigate to the site
+and provide the JSON export (or a file) to render the statistics. The number of
+rendered fields might differ based on your Nix version or implementation (Lix,
+Snix, etc.) Please crate an issue if the render looks wrong or incorrect.
+
+## Hacking
+
+`nix-evaluator-stats` (or "ns" for short) is built with Vite, using
+Typescript-React (`.tsx`) and SolidJS. A Nix shell is provided, and NPM
+dependencies can be fetched with `pnpm` while inside the dev shell.
+
+```bash
+# Run the live server
+$ pnpm run dev
+
+# Build a static site
+$ pnpm run build
+```
+
+If submitting pull requests, please ensure that format (`pnpm run fmt`) and lint
+(`pnpm run lint`) tasks are ran beforehand.
+
+## License
+
+<!-- markdownlint-disable MD059 -->
+
+This project is made available under Mozilla Public License (MPL) version 2.0.
+See [LICENSE](LICENSE) for more details on the exact conditions. An online copy
+is provided [here](https://www.mozilla.org/en-US/MPL/2.0/).
+
+<!-- markdownlint-enable MD059 -->