Document NPM_TOKEN for automatic publishing

.prettierignore

@@ -5,6 +5,8 @@
 !GOVERNANCE.md
 !eslint.config.js
 
+!/docs/publishing.md
+
 !/features/*.yml
 /features/*.yml.dist
 

docs/publishing.md

@@ -0,0 +1,23 @@
+# Publishing
+
+## `@next` releases
+
+The [`publish_next_` GitHub Actions workflows](https://github.com/web-platform-dx/web-features/tree/main/.github/workflows) automatically publish pre-releases on push to the main branch using the `next` [npm dist tag](https://docs.npmjs.com/adding-dist-tags-to-packages).
+You can install these prereleases using a command such as `npm install web-features@next`.
+
+## Secrets
+
+> [!NOTE]
+> This information is for [project owners](../GOVERNANCE.md#roles-and-responsibilities).
+
+Publishing requires the `NPM_TOKEN` repository secret (set via _Settings_ → _Secrets and variables_ → _Actions_).
+If you're replacing this token, then use the following settings:
+
+| Setting                          | Value                                                                                                      |
+| -------------------------------- | ---------------------------------------------------------------------------------------------------------- |
+| Token type                       | _Granular Access Token_                                                                                    |
+| Expiration                       | The first day of the next quarter (1 January, 1 April, 1 July, or 1 October) or the first weekday after it |
+| Packages and scopes permsissions | _Read and write_                                                                                           |
+| Select packages                  | _Only select packages and scopes_                                                                          |
+| Select packages and scopes       | `compute-baseline` and `web-features`                                                                      |
+| Organizations                    | _No access_                                                                                                |