Find a cross-tool method of standardizing version numbers

[artoonie]

Currently (after Issue #57 / PR #660), the version number needs to be synced in three places:

1. Main.java
2. build.gradle
3. release.yml

Figure out a way to have just one place to update. Note the issues with version tagging: we prefer Main.java to allow version tags (e.g. -alpha), but jpackage on some platforms (at least Windows) will not allow non-canonical version numbers. It must be in the format a.b.c, not a.b.c-alpha. Figure out a solution. Some ideas:

1. Perhaps we use 0.0.0 as version numbers in builds?
2. Perhaps we no longer use -alpha?
3. Perhaps we use -alpha and accept that `jpackage will fail, and argue that this is okay because we don't want nicely packaged development builds that could be confused with official releases, especially if they have the same version number?

(I lean towards 3 or 1.)

[HEdingfield]

I think this was actually after issue #57 / PR #660?

Thanks for researching this! I definitely like option 3 best, since we shouldn't bother doing jpackage builds for alpha versions anyway, like you mentioned (the whole alpha thing is really just a CYA convention we put in place in case someone demands a mid-cycle build for some purpose, in which case we can just give them the jlinkZip output).

[HEdingfield]

More discussion about this issue in #719 (comment).

Barring an easy win here, it may be sufficient to just note all the spots in the release instructions of our release procedure Wiki page here, which I just did.