Include the man page and man utilities in the Docker image.

docker/Dockerfile

@@ -83,10 +83,15 @@ RUN apk -U add \
         ffmpeg \
         libsodium \
         libgcrypt \
-        libplist
+        libplist \
+        mandoc \
+        man-pages \
+        less \
+        less-doc
 
 # Copy build files.
 COPY --from=builder /shairport-sync/build/install/usr/local/bin/shairport-sync /usr/local/bin/shairport-sync
+COPY --from=builder /shairport-sync/build/install/usr/local/share/man/man7 /usr/share/man/man7
 COPY --from=builder /usr/local/bin/nqptp /usr/local/bin/nqptp
 COPY --from=builder /usr/local/lib/libalac.* /usr/local/lib/
 COPY --from=builder /shairport-sync/build/install/etc/shairport-sync.conf /etc/

docker/classic/Dockerfile

@@ -62,11 +62,15 @@ RUN apk -U add \
         avahi-tools \
         libconfig \
         mosquitto \
-        libsndfile-dev
-
+        libsndfile-dev \
+        mandoc \
+        man-pages \
+        less \
+        less-doc
 
 # Copy build files.
 COPY --from=builder /shairport-sync/build/install/usr/local/bin/shairport-sync /usr/local/bin/shairport-sync
+COPY --from=builder /shairport-sync/build/install/usr/local/share/man/man7 /usr/share/man/man7
 COPY --from=builder /usr/local/lib/libalac.* /usr/local/lib/
 COPY --from=builder /shairport-sync/build/install/etc/shairport-sync.conf /etc/
 COPY --from=builder /shairport-sync/build/install/etc/shairport-sync.conf.sample /etc/