Added -i flag to all rm statements, Updated README

[hugo-hamet]

PR created after issue #9

After getting my PC's home directory wiped out, I decided to modify some of the code for it to be safer.

What caused the issue was this part of the code:

TLauncherName=$(basename *.jar .jar)
TLauncherDir="$HOME/${TLauncherName}"

[...]

rm -rf $TLauncherDir

Firstly, you should never assume that the user wants the TLauncherDir elsewhere than in the repository. Creating a flag for the script to adapt to this would be a great addition.
Next, note this: if there is no .jar file in the repository's directory, the TLauncherName variable will be set to * (try running echo $(basename *.jar .jar) in the cloned repository). The problem comes here: TLauncherDir is then set to $HOME/*
The rm -rf $TLauncherDir statement then deletes recursively $HOME/*, that is every folder existing in the user's home directory.

The addition of a -i flag to each rm statements is what allows the user to see each file that is about to get deleted, and refuse its deletion if an error occurs. I made sure the README explains it too:
"⚠️ Careful! During the execution of setup.py, you will be prompted by rm -rf statements. Respond y if you want the file deleted, or n if not."