Add documentation

Author: silvanocerza

README.md

@@ -1,12 +1,46 @@
-# create-changelog
+# Create Changelog
 
 [![Actions Status](https://github.com/arduino/create-changelog/workflows/Test%20Action/badge.svg)](https://github.com/arduino/create-changelog/actions)
 
-This actions create
+This actions is an highly opinionated tool that creates changelogs from the git repository commit history.
+
+If no property is set the changelog will be created from the current commit to the previous existing tag or the first commit.
 
 ## Usage
 
-TODO
+This action is meant to be launched inside a Git repository, thus the current `working-directory` must be set accordingly or it will fail.
+
+The action accepts some properties:
+
+- `tag-regex` to pick which tags are taken into consideration to create the changelog, the example below would ignore all tags except those matching it, `0.0.1` would be accepted but `v0.0.1` or `0.0.1-rc` would be ignored.
+  By default any tag is used.
+
+```
+      - name: Create Changelog
+        uses: arduino/create-changelog@v1
+        with:
+          tag-regex: '^[0-9]+\.[0-9]+\.[0-9]+$'
+```
+
+- `filter-regex` to skip certain commmits based on their message, the example below would skip all commits that start with the `[skip]` string.
+  By default no commit is skipped.
+
+```
+      - name: Create Changelog
+        uses: arduino/create-changelog@v1
+        with:
+          filter-regex: '^\[skip\].*'
+```
+
+- `changelog-file-path` to select the path and the name of the changelog file to be saved, the example below would save a `MyChangelog.md` file to the current `working-directory`.
+  By default `CHANGELOG.md` is used.
+
+```
+      - name: Create Changelog
+        uses: arduino/create-changelog@v1
+        with:
+          changelog-file-path: 'MyChangelog.md'
+```
 
 ## Development
 

action.yml

@@ -1,9 +1,19 @@
-name: "Create changelog"
-description: "Generates a changelog from a Git repository commit history."
-author: "Arduino"
+name: 'Create changelog'
+description: 'Generates a changelog from a Git repository commit history.'
+author: 'Arduino'
 runs:
-  using: "node12"
-  main: "dist/index.js"
+  using: 'node12'
+  main: 'dist/index.js'
 branding:
-  icon: "list"
-  color: "blue"
+  icon: 'list'
+  color: 'blue'
+inputs:
+  tag-regex:
+    description: 'Regex to select git tags used as boundaries for the changelog.'
+    default: ''
+  filter-regex:
+    description: 'Regex to filter out commit messages from the changelog.'
+    default: ''
+  changelog-file-path:
+    description: 'Destination file of the generated changelog.'
+    default: 'CHANGELOG.md'

src/settings.ts

@@ -2,10 +2,13 @@ import * as core from '@actions/core'
 import * as io from '@actions/io'
 
 export interface Settings {
-  // TODO: DOCS
+  // Path to git executable
   gitPath: string
+  // Regex to select git tags used as boundaries for the changelog
   tagRegex: string | RegExp
+  // Regex to filter out commit messages from the changelog
   filterRegex: string | RegExp
+  // Destination file of the generated changelog
   changelogFilePath: string
 }