new file: debian/README.source (#592)

Describes how to build

Author: stappersg

debian/README.source

@@ -0,0 +1,62 @@
+#
+# Juli Augustus 2025 was building the downloadable Debian packages done
+# by github.com CI, meaning you being depended on github.com
+# for getting a .deb of the libre source code (four GNU freedoms) you have.
+#
+# And in those days there was no official Debian package.
+#
+# What follows are instructions that make it possible to do
+# a succesfull
+#
+#   debuild -uc -us
+#
+# in the directory  target/rustdesk-server
+#
+# The instructions are written in bash syntax,
+#
+#   bash debian/README.source
+#
+# should help you immens
+#
+
+# Make sure the submodules are present
+git submodule update --init --recursive
+
+rm -rf target/rustdesk-server  # avoid clutter from previous iteration
+mkdir -p target/rustdesk-server #  FYI: target/ is ignored by git
+
+tar cf - \
+    --exclude .git \
+    Cargo.toml Cargo.lock \
+	LICENSE README.md \
+    db_v2.sqlite3 \
+	build.rs \
+	debian \
+	libs rcd src \
+    systemd ui \
+| ( cd target/rustdesk-server && tar x )
+
+mv target/rustdesk-server/debian/Makefile target/rustdesk-server/
+
+tar cjf target/rustdesk-server-orig.tar.xz \
+    --strip-components=1 \
+    target/rustdesk-server
+
+# an .orig.tar.xz tarball exists, 
+# work on the debian directory 
+
+eval $( dpkg-architecture )
+sed -e "s/{{ ARCH }}/${DEB_TARGET_ARCH}/" \
+    debian/control.tpl > target/rustdesk-server/debian/control
+    
+
+cd target/rustdesk-server
+dpkg-checkbuilddeps || echo sudo apt install dpkg-dev
+debuild -uc -us
+
+#
+# For what it is worth:
+# Early September 2025 there were
+# several WARNINGS and ERRORS from Lintian
+#
+# l l