add infos and installation instructions

README.md

@@ -1,2 +1,48 @@
 # dapnet2ntfy
 
+**dapnet2ntfy** forwards messages from the [DAPNET](https://hampager.de/) to [ntfy](https://ntfy.sh/).
+
+Similar to other [gateways](https://hampager.de/dokuwiki/doku.php#gateways_apps), especially the [Telegram Bot DB0USD](https://hampager.de/dokuwiki/doku.php?id=usecasetelegrambot), it allows receiving messages, when there is no pager with reception at hand.
+
+## Prerequisites
+
+### DAPNET account
+
+A normal account at [hampager.de](https://support.hampager.de/open.php) (select 'Help Topic -> New DAPNET Account with or without RIC').
+
+A transmitter registered at [hampager.de](https://support.hampager.de/open.php) (select 'Help Topic -> New DAPNET Transmitter').
+
+### ntfy account
+
+Use ntfy.sh or set up your own server: [DOCS](https://docs.ntfy.sh/).
+
+### perl modules
+
+- IO::Socket::INET
+- IO::Socket::Timeout
+- Errno
+- HTTP::Request
+- LWP::UserAgent
+- MIME::Base64
+- POSIX
+- utf8
+
+#### For Debian:
+
+```console
+apt install perl-base libio-socket-timeout-perl libhttp-message-perl libwww-perl
+```
+
+## Installation
+
+Instructions for installing the script to $HOME/bin/
+```console
+systemctl --user daemon-reload
+mkdir -p $HOME/.config/systemd/user/
+cp dapnet2ntfy.service $HOME/.config/systemd/user/
+mkdir -p $HOME/bin
+install -m 700 dapnet2ntfy.pl $HOME/bin/
+# edit the configuration section to your needs
+systemctl --user daemon-reload
+systemctl --user enable dapnet2ntfy.service --now
+```