Add lilypond package support

Added lilypond to the Docker image to enable music notation rendering in AsciiDoc documents. This package is available from Alpine's edge/testing repository and allows users to generate musical scores within their documentation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: benjamingarcia

Dockerfile

@@ -88,6 +88,7 @@ RUN apk add --no-cache \
   unzip \
   which \
   font-noto-cjk \
+  lilypond \
   && apk add --no-cache -X http://dl-cdn.alpinelinux.org/alpine/edge/testing \
   pdf2svg
 

tests/asciidoctor.bats

@@ -315,3 +315,8 @@ teardown() {
 
   grep 'Mane' ${TMP_GENERATION_DIR}/sample-with-bib.html
 }
+
+@test "lilypond is installed and in the path" {
+  docker run -t --rm "${DOCKER_IMAGE_NAME_TO_TEST}" which lilypond
+  docker run -t --rm "${DOCKER_IMAGE_NAME_TO_TEST}" lilypond --version
+}