Enable parallel building

.gitea/workflows/build.yaml

@@ -22,7 +22,7 @@ jobs:
         run: git clone https://git.0x45.cz/em/mixtape.git /workspace/em/mixtape
 
       - name: Build Chordpro
-        run: make pdf html songbook
+        run: make -j2 pdf html songbook
 
       - name: Build Zola
         run: zola build

makefile

@@ -1,7 +1,7 @@
 ifdef CHORDPRO_PIPELINE
 	CHORDPRO_CMD = chordpro
 else
-	CHORDPRO_CMD = docker run -ti --rm \
+	CHORDPRO_CMD = docker run --rm \
 		--env HOME=$(HOME) --env USER=$(USER) \
 		--workdir $(shell pwd) \
 		--volume $(HOME):$(HOME) \

readme.md

@@ -26,6 +26,12 @@ Target | Description
 `songbook` | Build one complete PDF songbook with all songs
 `clean` | Remove all generated files
 
+The makefile is ready for parallel building:
+
+```
+make -j$(nproc)
+```
+
 You can also build PDF for a specific page with:
 
 ```