[README.md] Added Instalation section.

README.md

@@ -19,4 +19,30 @@ comma separated list of ONLY running process' names.
 Configuration file is a simple key = value storage consisting of `listen_address` string
 field in form `"[<ip|host>]:<port>"`. `indented_output` bool in form `true|false`, to
 enable indentation of JSON and XML output. And `processes` is a space separated array
-of process names.
+of process names.
+
+## Installation
+
+### Manually
+
+Run these commands one after the other.
+
+```console
+$ make
+$ make install
+$ make install-service
+```
+
+In order to uninstall run these commands:
+
+```console
+# systemctl stop httpprocwatchd
+# systemctl disable httpprocwatchd
+$ make uninstall-service
+$ make uninstall
+# systemctl daemon-reload
+```
+
+### For ArchLinux
+
+You can take a [PKGBUILD](/Arav/httpprocwatchd/raw/branch/master/contrib/archlinux/PKGBUILD) file and in a directory with it run `makepkg -i`.