Add deb and RPM repository config and documentation (#1676)

Co-authored-by: Parity Releases <releases@parity.io>
Co-authored-by: Demi Marie Obenour <demiobenour@gmail.com>

polkadot/.rpm/polkadot.spec

@@ -0,0 +1,48 @@
+%define debug_package %{nil}
+
+Name: polkadot
+Summary: Implementation of a https://polkadot.network node in Rust based on the Substrate framework.
+Version: @@VERSION@@
+Release: @@RELEASE@@%{?dist}
+License: GPLv3
+Group: Applications/System
+Source0: %{name}-%{version}.tar.gz
+
+Requires: systemd, shadow-utils
+Requires(post): systemd
+Requires(preun): systemd
+Requires(postun): systemd
+
+BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
+
+%description
+%{summary}
+
+
+%prep
+%setup -q
+
+
+%install
+rm -rf %{buildroot}
+mkdir -p %{buildroot}
+cp -a * %{buildroot}
+
+%post
+config_file="/etc/default/polkadot"
+getent group polkadot >/dev/null || groupadd -r polkadot
+getent passwd polkadot >/dev/null || \
+    useradd -r -g polkadot -d /home/polkadot -m -s /sbin/nologin \
+    -c "User account for running polkadot as a service" polkadot
+if [ ! -e "$config_file" ]; then
+    echo 'POLKADOT_CLI_ARGS=""' > /etc/default/polkadot
+fi
+exit 0
+
+%clean
+rm -rf %{buildroot}
+
+%files
+%defattr(-,root,root,-)
+%{_bindir}/*
+/usr/lib/systemd/system/polkadot.service