Update README.md (#4)

README.md

@@ -1,2 +1,31 @@
 # cairo-toolchain-xtasks
-Build scripts shared between all Cairo Toolchain projects of ours.
+
+Build scripts that are shared between all Cairo Toolchain projects of Software Mansion.
+
+## Usage
+
+We release this crate to [crates.io](https://crates.io/crates/cairo-toolchain-xtasks).
+Put this crate as a dependency in your `xtask/Cargo.toml`:
+
+```toml
+[dependencies]
+cairo-toolchain-xtasks = "1"
+```
+
+Using major-specific version spec helps Dependabot pick up new versions.
+For further details, copy-paste the logic from other projects, like Scarb or CairoLS.
+
+## Development
+
+Try as much as possible to not break existing workflows anywhere.
+Follow semantic versioning.
+Ideally, it'd be the best for this crate to always be backwards-compatible and stay on `1` major version number.
+
+To ship your changes, just `cargo publish` a new release to crates.io.
+Then make sure the project of your interest `Cargo.lock` points to the new release.
+No need to update other projects, Dependabot will do this job for you sometime in the future.
+
+### Adding a new toolchain project
+
+If you're working on a new Cairo Toolchain project,
+make sure you add all necessary information in [`src/upgrade.rs`](src/upgrade.rs) xtask.