Adding a new method of hosting - service/daemon

[HostServer001]

Hello,
I use catuserbot for quite a while now, since Heruko started banning users for deploying userbots the hosting has been difficult.
This led to local hosting, one way was to self host and the other was to use docker . Self host is a painful method , even the documentation mentions that and docker is a resource heavy method which is not suitable for RAM and compute starving PC/Laptop. Hence, we need a option which is not painful as self host and as resource heavy as docker. I think that daemonization is the suitable to fulfill this purpose . It is managed by systemd and has its own venv so not painful as self host and since runs directly on pc/laptop not that resource heavy. In this PR i have added two files , install_as_service.py and _install_checker.py , the former is a script to install the userbot after user has written his .env file and the latter is a script to check if the config variables are okay or not.
This script is designed to minimize user interaction, it is almost a plug and play script.
One downside is that it requires sudo cause we are making a .service file and also installing packages like uv.
But i have tried to make it log every command it runs.

I have also added the gitbook docs for this method along with changing the documentation on config vars which referenced to config.py which is replaced by .env .

Thank you for your time , hope you find this PR valuable and helpful .
I am also willing to help in documentation, as someone requested for help in the telegram channel

TLDR-
Things changed
two new files added for new method of hosting

• install_as_service.py
• _install_checker.py
• added documentation for this method
• changed the old documentation on config vars which referenced use of config.py file

EDIT-
As i was reviewing my own work, i realized some bugs and security issues that may arrive in future.

• Added aditional file uv-installer.sh , so script dont need to curl and pipe
• Changed bad logic in database_setup which was altering the password silently before even checking whether data base exists
• removed shell = True argument from the subprocess.run , minimizing the risk of command injection

[Jisan09]

small install_checker.py markdown fix need

[Jisan09]

make it without uv or use pip install uv given on their install process instead of copying whole script