Fix configuration settings (#43, #42)

[igorechek06]

• Closes: LSP server settings has no effect #42
• Closes: Formatter does not work #43

I just read nvim-jdtls configuration example and make hypotheses about jdtls.
And it turned out, the settings field in InitializationOptions is a field in DidChangeConfigurationParams.
It is so..... stupid.

[igorechek06]

This is the first time when documentation and examples lie to me.

[valentinegb]

Whoa, this is big if you're right O.O
Have you tested this?

[igorechek06]

Yes I did. Works great. (I tested formating only 😅)

[igorechek06]

I tested some options right now. Finally I can disable auto build option. But I can't disable completion.guessMethodArguments. So weird.
"format" and "signatureHelp" also works.

[igorechek06]

I find this documentation. JDTLS documentation completely broken.

[valentinegb]

Oops- didn't mean to remove you as an author of the commit- if you know how, feel free to amend it and force push so that you're a co-author like I intended ^^'

[notpeter]

Oops- didn't mean to remove you as an author of the commit- if you know how, feel free to amend it and force push so that you're a co-author like I intended ^^'

@valentinegb You can also manually add Co-Authored-By: with the info from the original commit in the description when you squash and merge.