added the quick and dirty way of installing in readme

ich hab die schritte ins readme geschrieben die du mir erklärt hast wenn ich swet in einem virtual environment ausführen möchte.

basiert auf auf meinen kommentar in dem issue #2.

README.md

 SWET für SWEB
 ==============
 
-SWET (Schon wieder ein Testsystem) is a Testrunner for 
+SWET (Schon wieder ein Testsystem) is a Testrunner for
 [SWEB](https://github.com/iaik/sweb) (Schon wieder ein Betriebssystem).
 SWET makes all the necessary patches to sweb, injects the tests and detects if
 the test succeeded or failed.
@@ -11,14 +11,14 @@ Installation
 =============
 
 SWET can be installed via ```pip```.
-However, the package is not beeing distributed via [PyPI](https://pypi.org) 
+However, the package is not beeing distributed via [PyPI](https://pypi.org)
 but via the gitlab package registry.
 
 
 Installation of SWET
 ---------------------
 
-Since this is a private repository, it is manditory to use a personal access 
+Since this is a private repository, it is manditory to use a personal access
 token to interact with the package-registry.
 
 [Gitlab Personal Access Token: Create an Access Token](https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html#create-a-personal-access-token)
@@ -33,7 +33,19 @@ $
 TODO: Add URL once the package was published the first time
 -->
 
+---
 
+The fast way of using SWET is to install it as a `pip` package inside a virtual environment.
+
+This is the code you have to run inside the root direcory of this repository in order to use SWET as `swet` inside your terminal.
+
+```
+python -m venv venv
+. ./venv/bin activate
+pip install -e .
+```
+
+>Please Note that the package only exists as long as the `venv` does.
 
 Writing of SWET-Tests
 =====================
@@ -121,5 +133,3 @@ Installation & Setup
 $ pip install tox pre-commit
 $ pre-commit install
 ~~~
-
-