Add publish-new-version.sh for pushing versions of the crate

[acmcarther]

Adds a script for publishing new versions of this crate to codify my shell history into a shell script usable by other folks.

Has some rudimentary checks for the existence of cargo and that the working directory is clean.

r: @UebelAndre as well

[UebelAndre]

@acmcarther Are there also some examples of using this script? Whenever I add things like this to projects at work, I typically add a block of comments at the top of the file that show simple usage just to make it crystal clear as to what to do.

# Use the script like so
# Args: ...docs...
#
# ./my_script.sh arg1 arg2

# Use the script like so
# Environment: ...docs...
#
# ARG_VAR=1 ./my_other_script.sh

Things like that.

While It's unlikely I'll be doing a deploy for this so If there's some internal Google doc that has this, that works as well. The thing I want to avoid is all maintainers who have familiarity with the project/script being unavailable and therefore no more releases happen because maybe some constraint changed or things are not as obvious to the available/new maintainers.

Whether or not you decide to do that, I'm thankful for this PR! 😄

[acmcarther]

Thanks, that's valuable feedback.

I've added some documentation about what the script does and how to use it to the top of the file. Incidentally, I've also updated the mechanism it uses to take in the new version from an environment variable to a regular argument.

[UebelAndre]

@acmcarther When the version is updated should the Cargo.lock file be updated too in the /tools directory?

[acmcarther]

Re #217 (comment)

I'm not really sure. I don't consider the contents of tools/ to be part of the package proper though, so i think it's OK to punt on this question for now.

That said, this should be a consideration in handling #210 I think.

[UebelAndre]

As a quick followup. Do you think you could delete some old branches? 😅

[acmcarther]

Done!