Update CONTRIBUTING.md (#1105)

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -19,7 +19,7 @@ The Astro community is my personal attempt to share this experience with others
 - **preventing imposter syndrome:** Sure, I was still just a kid, but having an actual human connection to developers who I looked up to at the time helped dispell the idea that "oh, **I** could never be like that."
 - **Making friends in the larger community:** The creator of request, [@mikeal](https://twitter.com/mikeal), is still a friend to this day.
 
-If any of this sounds interesting, I hope you consider getting involved with Astro. Come say hi in the **#new-contributors** channel on Discord, anytime. We're always around and value contributions of any shape/size.
+If any of this sounds interesting, I hope you consider getting involved with Astro. Come say hi in the [**#new-contributors**](https://astro.build/chat) channel on Discord, anytime. We're always around and value contributions of any shape/size.
 
 # Contributor Manual
 
@@ -28,62 +28,34 @@ If any of this sounds interesting, I hope you consider getting involved with Ast
 ```shell
 node: "^12.20.0 || ^14.13.1 || >=16.0.0"
 yarn: "^1.22.10"
-# otherwise, build will fail
+# otherwise, your build will fail
 ```
 
-## Setting Up the Monorepo
+## Setting up the monorepo
 
 ```shell
 # git clone && cd ...
 yarn install
+yarn build:all
+```
+
+## Development
+
+```shell
+# starts a file-watching, live-reloading dev script for active development
+yarn dev
+# (optional) trigger a one-time build
 yarn build
 ```
 
-Most of the packages have a dev script that will recompile when a file changes. For example when working on the `astro` package you can run:
+## Making a Pull Request
 
-```shell
+When making a pull request, be sure to add a changeset when something has changed with Astro. Non-packages (`examples/*`, `docs/*`, and `www/*`) do not need changesets.
-yarn workspace astro run dev
-```
-
-## Making Pull Requests
-
-When making a pull request, add a changeset which helps with releases.
 
 ```shell
 yarn changeset
 ```
 
-This will prompt you asking what type of change was made.
-
-## Releases
-
-For those contributors that have access to publish to npm, the following is how you do releases.
-
-From the `main` branch do a pull, install and build:
-
-```shell
-git pull origin main
-yarn install
-yarn build
-```
-
-Then bump the versions:
-
-```shell
-yarn changeset version
-```
-
-This should change package.json bumping version numbers and update changelogs. Inspect these to make sure they are what you expect.
-
-Commit and push these changes, then run an npm publish for each of the packages that have changed.
-
-> **Important**! Ordering publishes can be important. If `@astrojs/parser` changes you should publish that before `astro`, for example.
-
-```shell
-cd packages/astro
-npm publish
-```
-
 ## Running benchmarks
 
 We have benchmarks to keep performance under control. You can run these by running (from the project root):
@@ -103,7 +75,56 @@ node test/benchmark/dev.bench.js --save
 
 Which will update the build and dev benchmarks.
 
-## Translations
+
+# Releasing Astro
+
+_Note: Only priviledged contributors (L3+) can release new versions of Astro._
+
+The repo is set up with automatic releases, using the changeset GitHub action & bot. 
+
+To release a new version of Astro, find the `Version Packages` PR, read it over, and merge it.
+
+## Releasing PR preview snapshots
+
+Our release tool `changeset` has a feature for releasing "snapshot" releases from a PR or custom branch. These are npm package publishes that live temporarily, so that you can give users a way to test a PR before merging. This can be a great way to get early user feedback while still in the PR review process.
+
+To release a snapshot, run the following locally:
+
+```shell
+# Note: XXX should be a keyword to identify this release. Ex: `--snapshot routing` & `--tag next--routing`
+
+# 1:
+yarn changeset version --snapshot XXX
+# 2: (Manual) review the diff, and make sure that you're not releasing more than you need to.
+git checkout -- examples/ docs/ www/
+# 3:
+yarn release --tag next--XXX
+```
+
+Full documentation: https://github.com/atlassian/changesets/blob/main/docs/snapshot-releases.md
+
+
+
+## Releasing in "next"/"pre" mode
+
+Sometimes, the repo enters "next" mode, which means that `main` is no longer releasing to `npm install astro` but is instead releasing to `npm install astro@next`. We do this from time-to-time to test large features before sharing them with the larger Astro audience.
+
+When in "next" mode, the automatic PR release process is for `next`. That means that releasing to `latest` becomes a manual process. To release latest manually while in "next" mode:
+
+1. *In the code snippets below, replace `0.X` with your version (ex: `0.18`, `release/0.18`, etc.).*
+1. Create a new `release/0.X` branch, if none exists. 
+1. Point `release/0.X` to the latest commit for the `v0.X` version.
+1. `git cherry-pick` commits from `main`, as needed.
+1. Make sure that all changesets for the new release are included. You can create some manually (via `yarn changeset`) if needed.
+1. Run `yarn changeset version` to create your new release.
+1. Run `yarn release` to publish your new release.
+1. Run `git push && git push --tags` to push your new release to GitHub.
+1. Run `git push release/0.X:latest` to push your release branch to `latest`. This will trigger an update to the docs site, the www site, etc.
+1. Go to https://github.com/snowpackjs/astro/releases/new and create a new release. Copy the new changelog entry from https://github.com/snowpackjs/astro/blob/latest/packages/astro/CHANGELOG.md.
+1. Post in Discord #announcements channel, if needed!
+
+
+# Translations
 
 Help us translate [docs.astro.build](https://docs.astro.build/) into as many languages as possible! This can be a great way to get involved with open source development without having to code.