Update hacking docs

uncloud/docs/source/hacking.rst

@@ -1,17 +1,25 @@
 Hacking
 =======
-How to hack on the code.
+Using uncloud in hacking (aka development) mode.
 
-[ to be done by Balazs:
 
-* make nice
-* indent with shell script mode
+Get the code
+------------
+.. code-block:: sh
+    :linenos:
 
-]
+     git clone https://code.ungleich.ch/uncloud/uncloud.git
 
-* git clone the repo
-* cd to the repo
-* Setup your venv: python -m venv venv
-* . ./venv/bin/activate # you need the leading dot for sourcing!
-* Run ./bin/ucloud-run-reinstall - it should print you an error
-  message on how to use ucloud
+
+
+Install python requirements
+---------------------------
+You need to have python3 installed.
+
+.. code-block:: sh
+    :linenos:
+
+    cd uncloud!
+    python -m venv venv
+    . ./venv/bin/activate
+    ./bin/uncloud-run-reinstall