feat: cargo watch for wasm build

Signed-off-by: Lachezar Lechev <lachezar@ambire.com>

.cargo/config.toml

@@ -0,0 +1,5 @@
+
+
+[alias]
+# Requires cargo-watch
+watch-wasm = ["watch", "--shell", "./scripts/build.sh --dev"]

README.md

@@ -9,7 +9,7 @@ Bridge between [stremio-core](https://github.com/stremio/stremio-core) and [stre
 
 Builds a production wasm package and prepares the rest of the dependencies for the npm package.
 
-```
+```bash
 npm install
 npm run build
 ```
@@ -18,10 +18,19 @@ npm run build
 
 Building the package using [`./scripts/build.sh`](./scripts/build.sh) with `--dev` would allow you to see more logging messages being emitted, this is intended **only** for debugging as it will log messages with sensitive information!
 
-```
+```bash
 ./scripts/build.sh --dev
 ```
 
+Or you can also use the development-specific Rust's `wasm-watch` alias from [`./.cargo/config.toml`](./.cargo/config.toml).
+It will automatically re-compile the package when a change on the files or dependencies is detected,
+including when you're using a local patch for `stremio-core`.
+
+1. Install `cargo-watch`
+   - `cargo install cargo-watch`
+   - With `cargo-binstall` (prebuilt binaries): `cargo binstall cargo-watch`
+2. Run `cargo wasm-watch`
+
 ## Publishing
 
 1. Update version to the next minor/major/patch version in Cargo (`Cargo.toml` and `Cargo.lock`) and npm (`package.json` and `package-lock.json`), e.g. from `0.44.13` to `0.44.14`.