feat: add the prepare plugin hook

BREAKING CHANGE: Committing or creating files in the `publish` plugin hook is not supported anymore and now must be done in the `prepare` hook

Plugins with a `publish` hook that makes a commit or create a file that can be committed must use the `prepare` hook.

docs/extending/plugins-list.md

@@ -9,6 +9,7 @@
   - [fail](https://github.com/semantic-release/github#fail): Open a GitHub issue when a release fails
 - [@semantic-release/npm](https://github.com/semantic-release/npm)
   - [verifyConditions](https://github.com/semantic-release/npm#verifyconditions): Verify the presence and the validity of the npm authentication and release configuration
+  - [prepare](https://github.com/semantic-release/npm#prepare): Update the package.json version and create the npm package tarball
   - [publish](https://github.com/semantic-release/npm#publish): Publish the package on the npm registry
 
 ## Official plugins
@@ -18,15 +19,16 @@
   - [publish](https://github.com/semantic-release/gitlab#publish): Publish a [GitLab release](https://docs.gitlab.com/ce/workflow/releases.html)
 - [@semantic-release/git](https://github.com/semantic-release/git)
   - [verifyConditions](https://github.com/semantic-release/git#verifyconditions): Verify the presence and the validity of the Git authentication and release configuration
-  - [publish](https://github.com/semantic-release/git#publish): Push a release commit and tag, including configurable files
+  - [prepare](https://github.com/semantic-release/git#prepare): Push a release commit and tag, including configurable files
 - [@semantic-release/changelog](https://github.com/semantic-release/changelog)
   - [verifyConditions](https://github.com/semantic-release/changelog#verifyconditions): Verify the presence and the validity of the configuration
-  - [publish](https://github.com/semantic-release/changelog#publish): Create or update the changelog file in the local project repository
+  - [prepare](https://github.com/semantic-release/changelog#prepare): Create or update the changelog file in the local project repository
 - [@semantic-release/exec](https://github.com/semantic-release/exec)
   - [verifyConditions](https://github.com/semantic-release/exec#verifyconditions): Execute a shell command to verify if the release should happen
   - [analyzeCommits](https://github.com/semantic-release/exec#analyzecommits): Execute a shell command to determine the type of release
   - [verifyRelease](https://github.com/semantic-release/exec#verifyrelease): Execute a shell command to verifying a release that was determined before and is about to be published.
   - [generateNotes](https://github.com/semantic-release/exec#analyzecommits): Execute a shell command to generate the release note
+  - [prepare](https://github.com/semantic-release/exec#prepare): Execute a shell command to prepare the release
   - [publish](https://github.com/semantic-release/exec#publish): Execute a shell command to publish the release
   - [success](https://github.com/semantic-release/exec#success): Execute a shell command to notify of a new release
   - [fail](https://github.com/semantic-release/exec#fail): Execute a shell command to notify of a failed release

docs/usage/configuration.md

@@ -155,6 +155,18 @@ Define the [generate notes plugin](plugins.md#generatenotes-plugin).
 
 See [Plugins configuration](plugins.md#configuration) for more details.
 
+### prepare
+
+Type: `Array`, `String`, `Object`
+
+Default: `['@semantic-release/npm']`
+
+CLI argument: `--prepare`
+
+Define the list of [prepare plugins](plugins.md#prepare-plugin). Plugins will run in series, in the order defined in the `Array`.
+
+See [Plugins configuration](plugins.md#configuration) for more details.
+
 ### publish
 
 Type: `Array`, `String`, `Object`

docs/usage/plugins.md

@@ -28,6 +28,14 @@ Plugin responsible for generating release notes.
 
 Default implementation: [@semantic-release/release-notes-generator](https://github.com/semantic-release/release-notes-generator).
 
+### prepare plugin
+
+Plugin responsible for preparing the release, including:
+- Creating or updating files such as `package.json`, `CHANGELOG.md`, documentation or compiled assets.
+- Create and push commits
+
+Default implementation: [npm](https://github.com/semantic-release/npm#prepare).
+
 ### publish plugin
 
 Plugin responsible for publishing the release.