Update installation instructions

Author: qtc-de

README.md

@@ -34,6 +34,12 @@ file and are accesses via *rofi*.
 *ctfcred* can be build and installed as a *pip package*. The following command installs *ctfcred*
 for your current user profile:
 
+```console
+$ pip3 install ctfcred
+```
+
+You can also build *ctfcred* from source by running the following commands:
+
 ```console
 $ git clone https://github.com/qtc-de/ctfcred
 $ cd ctfcred