Update references to the rizinrc config file

[nullun]

I started out PR'ing this to dev, but it seems like there's a few outstanding commits and the last two PR's have gone straight to master, so this too is set to master, but let me know if you want me to rebase on dev.

Updated a few references of ~/.rizinrc to be ~/.config/rizin/rizinrc. Both do appear to work, but thought it would be nice to be consistent. One of the instances was an old output of the command e? which I've also included an update for.

[ret2libc]

Shall we prefer ~/.rizinrc in the doc? That's where I usually place my configuration at least.

[nullun]

Yeah, I can switch it to that. Any technical reason other than personal preference? I noticed .config/rizin/rizinrc will trump .rizinrc if they're both set with different values.

[wargio]

Shall we prefer ~/.rizinrc in the doc? That's where I usually place my configuration at least.

that is also mine. but i guess we could also mention other locations.

[XVilka]

I personally prefer in .config since it's the XDG standard and prevents clogging your HOME.

[nullun]

rizin -H states RZ_RCONFIGHOME=/home/nullun/.config/rizin as being the default configuration location for me and I haven't changed anything, but the files page in the book does suggest ~/.rizinrc as being a valid alternative which also works.

I'm in favour of using XDG standards to keep my home directory clean, but maybe we could add links to the above files page in all the places .config/rizin/rizinrc is shown?

[wargio]

if that is the output of the home location, than yes. that would be what should have been on the docs.