README: document that automake is installed by default, add minimal example

README.md

@@ -16,7 +16,7 @@ All of the following inputs are optional.
 
 - `pkgs-to-install`:
     - Comma-separated list containing the Cygwin packages needed to install GAP
-    - default: `'wget,git,gcc-g++,gcc-core,libgmp-devel,make,libtool,autoconf,zlib-devel,libreadline-devel,xdg-utils'`
+    - default: `'wget,git,gcc-g++,gcc-core,libgmp-devel,make,libtool,autoconf,zlib-devel,libreadline-devel,xdg-utils,automake'`
 - `extra-pkgs-to-install`:
     - Comma-separated list containing the extra Cygwin packages needed to install additional packages
     - default: `''`
@@ -31,6 +31,29 @@ issue and possibly revert to v1).
 Moreover the `EXTRA_PKGS_TO_INSTALL` input was renamed to `extra-pkgs-to-install`,
 and `PKGS_TO_INSTALL` was renamed to `pkgs-to-install`.
 
+### Examples
+
+The following is a minimal example to run this action.
+
+```yaml
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  # The CI test job
+  test:
+    name: CI test
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v6
+      - uses: gap-actions/setup-cygwin@v2
+      # ... additional steps using GAP will usually follow here
+```
+
 ## Contact
 Please submit bug reports, suggestions for improvements and patches via
 the [issue tracker](https://github.com/gap-actions/setup-cygwin/issues).