readme: include --help text

README.md

@@ -21,16 +21,76 @@ Several things will happen if one elects to continue:
     git push --atomic origin refs/heads/master refs/tags/v0.6.1
     env VERSION=0.6.1 PREVIOUS_VERSION=0.6.0 bash -c 'npm publish'
 
-xyz accepts several optional arguments, described in the help text:
+## Usage
 
-    $ xyz --help
+    Usage: xyz [options]
 
-### Integration
+    Publish a new version of the npm package in the current working directory.
+    This involves updating the version number in package.json, committing this
+    change (along with any staged changes), tagging the commit, pushing to the
+    remote git repository, and finally publishing to the public npm registry.
+
+    Options:
+
+    -b --branch <name>
+            Specify the branch from which new versions must be published.
+            xyz aborts if run from any other branch to prevent accidental
+            publication of feature branches. 'master' is assumed if this
+            option is omitted.
+
+    -e --edit
+            Allow the commit message to be edited before the commit is made.
+
+    -i --increment <level>
+            Specify the level of the current version number to increment.
+            Valid levels: 'major', 'minor', 'patch', 'premajor', 'preminor',
+            'prepatch', and 'prerelease'. 'patch' is assumed if this option
+            is omitted.
+
+    -m --message <template>
+            Specify the format of the commit (and tag) message.
+            'X.Y.Z' acts as a placeholder for the version number.
+            'Version X.Y.Z' is assumed if this option is omitted.
+
+       --prerelease-label <label>
+            Specify the label to be used in the version number when publishing
+            a pre-release version (e.g. 'beta' is the label in '2.0.0-beta.0').
+            'rc' is assumed if this option is omitted.
+
+       --publish-command <command>
+            Specify the command to be run to publish the package. It may refer
+            to the VERSION and PREVIOUS_VERSION environment variables. A no-op
+            command (':' or 'true') prevents the package from being published
+            to a registry. 'npm publish' is assumed if this option is omitted.
+
+    -r --repo <repository>
+            Specify the remote repository to which to 'git push'.
+            The value must be either a URL or the name of a remote.
+            The latter is not recommended: it relies on local state.
+            'origin' is assumed if this option is omitted.
+
+    -s --script <path>
+            Specify a script to be run after the confirmation prompt.
+            It is passed VERSION and PREVIOUS_VERSION as environment
+            variables. xyz aborts if the script's exit code is not 0.
+
+    -t --tag <template>
+            Specify the format of the tag name. As with --message,
+            'X.Y.Z' acts as a placeholder for the version number.
+            'vX.Y.Z' is assumed if this option is omitted.
+
+       --dry-run
+            Print the commands without evaluating them.
+
+    -v --version
+            Print xyz's version number and exit.
+
+## Integration
 
 Installing xyz globally is okay, but it's good practice to add it as a dev
 dependency.
 
-#### npm
+### npm
 
 ```json
   "scripts": {
@@ -42,7 +102,7 @@ dependency.
 $ npm run release minor
 ```
 
-#### Make
+### Make
 
 ```make
 XYZ = node_modules/.bin/xyz --repo git@github.com:owner/repo.git