use mvn site to generate javadoc jar

[jodygarnett]

Move javadoc to phase site:

• mvn clean install - just builds jar and source jar
• mvn site - builds javadoc jar

Note the javadoc generation has warnings and errors at present...

[jodygarnett]

@jnh5y this PR is "functional", not sure if we want it? I believe we addressed the javadoc warning issues discussed above.

[jnh5y]

@jodygarnett why do you want to leave the generation of the javadocs to mvn site? I'm confused.

[jodygarnett]

I think this is left over from when we first migrated to maven. There are two options for where to hook in javadocs...

• We could set it up as a "report" so it would show up in mvn site build
• We could bind it to a stage (so for example it would show up in a full mvn install build)

Or we could do nothing and depend on mvn javadoc:javadoc like we do now?

I recommend we close this pull request, unless you are used to (or like the sound of) the mvn site approach?