[analyzer_plugin] getting started page is outdated

[FMorschel]

I know this may still be under lots of changes, but I thought I'd still warn @srawlins that the
analyzer_plugin's getting started page shows outdated information on what a minimal ServerPlugin looks like.

We may probably want to leave this open until the final launch, so we remember to, but maybe you already want to fix this @srawlins?

[bwilkerson]

@FMorschel Is this still valid given that analyzer_plugin is the old plugin support?

[FMorschel]

It isn't necessary, sorry.

I had on my TODO to review these recent ones today.

Thanks for noting!