Add instructions on publishing a new SDK version. (#53)

Author: ro-tex

PUBLISH.md

@@ -0,0 +1,52 @@
+# Instructions for publishing a new SDK version
+
+What this guide covers is how to publish a new SDK package on a package distribution network (where that applies), e.g.
+[NPM](https://www.npmjs.com/package/@chainlink/data-streams-sdk) for TypeScript
+or [crates.io](https://crates.io/crates/chainlink-data-streams-report) for Rust. As Go doesn't use a package system like
+that, the release process is limited to tagging a commit and creating a GitHub release.
+
+## Go
+
+1. Tag a `main` commit with `go/vX.Y.X`. This is enough for the new version to be considered released.
+2. Additionally, we can create a new release directly on GitHub. make sure to choose the correct tag, target, and
+   previous version/tag. That allows you to use the `Generate release notes` button to get a good starting point of the
+   release notes.
+
+## TypeScript
+
+1. Increment the version in `package.json` to what it should be.
+2. Run `npm i` in order to update `package-lock.json`.
+3. Trigger the `Manual NPM Publish for TS SDK` GitHub action.
+
+## Rust
+
+1. Increment the version in all `Cargo.toml` files:
+
+rust/crates/report/Cargo.toml:
+
+```
+[package]
+name = "chainlink-data-streams-report"
+- version = "1.1.0"
++ version = "1.2.0"
+```
+
+rust/crates/sdk/Cargo.toml:
+
+```
+[package]
+name = "chainlink-data-streams-sdk"
+- version = "1.1.0"
++ version = "1.2.0"
+
+...
+
+[dependencies]
+- chainlink-data-streams-report = { path = "../report", version = "1.1.0" }
++ chainlink-data-streams-report = { path = "../report", version = "1.2.0" }
+```
+
+2. Run `cargo build` and `cargo publish --dry-run` in order to update `Cargo.lock`.
+3. Trigger the `Publish Chainlink Data Streams Report Crate` and `Publish Chainlink Data Streams SDK Crate` GitHub
+   actions by pushing the respective `rust/chainlink-data-streams-report-v*` and `rust/chainlink-data-streams-sdk-v*`
+   tags.