Documentation suggests sudo make install

[MakisH]

The documentation currently encourages users to essentially do sudo make install:

aste/docs/README.md

Lines 80 to 86 in bdc3fbb

	In order to install ASTE and the associated tools system-wide, execute
	```bash
	make install
	```
	which might require root permission.

In the past, this has led to all kinds of confusions with users that manually installed preCICE in their system directories.

Suggestions:

1. Remove this hint
2. Add instructions on how to use from the build directory, or add the build directory to PATH
3. Add support to CMake for generating Debian packages, ask users to prepare and use these