[docs] Inform users about using `context.aslr` instead of non-exist `args.NOASLR`

[tesuji]

I tried to run pwn scripts with python solve.py NOASLR=True (or just =1, or just NOASLR).
There is no easy way to test if the script has been run by using args.NOASLR. The values in args that I could observe
are PwnlibArgs(<class 'str'>, {'EXE': '', 'PLT_DEBUG': '', 'PORT': '', 'REMOTE': '', 'DOCKER': '', 'GDB': ''}). It would be nice if we could add NOASLR to that dict.

[tesuji]

After dive into source code, I can see that context.aslr can be used for this case. Perhaps we could improve the docs on args.

[peace-maker]

Yes, NOASLR sets the default of context.aslr value.

https://github.com/Gallopsled/pwntools/blob/dev/pwnlib%2Fargs.py#L149

Where in the docs did you miss this connection? pwnlib.args?

[tesuji]

The default template uses the syntax args.<var> for REMOTE, HOST, USER, LOCAL. It says nothing about how to access NOASLR. Unless I access pwnlib.args.NOASLR? in ipython, which I didn't since args is more convenient, I have no idea about context.aslr.