Add a comment somewhere for adding rustic to PATH environment variable

[nickchomey]

I only just realized/figured out that I can add the rustic install/download path to my PATH environment variable so that you can just call rustic rather than /path/to/rustic.

So, while we wait for rustic-rs/rustic#114, I suggest just adding some instructions (or at least a comment) somewhere for adding this.

Good instructions here for adding to .bashrc and .bash_profile
https://unix.stackexchange.com/questions/26047/how-to-correctly-add-a-path-to-path

[aawsome]

Another possibility is to download rustic into a path which is already present in PATH - a natural choice would be /usr/local/bin which should be in PATH for most linux distros.

Actually I could only imagine to add comment to the installation instructions in the (upcoming) docu - this is nothing rustic-specific, but applies to all executables in the system...

[nickchomey]

Well, I think its reasonable to assume that a non-insignificant amount of people don't know much about executables - we tend to just install packages and the commands just work - perhaps specifically because they get installed to a path like /usr/local/bin...

So, perhaps it could just be suggested to download it to there (I just did that and, of course, it works well)? Again, this is just in lieu of having actual installable packages

[z3cko]

Don't most people actually install via cargo and then have their packages automatically in PATH? This is how I do it on all my systems (Linux and Mac)