Partially fixes #39

[kr1viah]

As said in the title, this partially fixes #39

To be more exact:

• Update to use implementation over modImplementation
• Fixes the inputs to FMJ to take in Minecraft version strings with -alpha. instead of -snapshot-
• Adds .toString() to the build.gradle.kts to fix it not launching at all

If desired, I could add something to separate using Kotlin as the DSL and using it as the language used in the mod.

[kr1viah]

Oh, actually, #if (${VERSIONS.minecraft.compareTo($mcver.MC1_21_11)} <= 0) doesn't work properly with 26.1, so that'll have to get fixed first