Document how hls can be configured

[jneira]

• Fow now the configuration section talks exclusively about the build info that hls needs to open a haskell project in a reliable way
• However, there is nothing about the settings that final users can change from their editors/lsp clients:
  • What formatter want to use for example
  • Several options were translated from hie and they still does not make sense, so they should not be documented yet

haskell-language-server/hls-plugin-api/src/Ide/Plugin/Config.hs

Lines 44 to 54 in 84a2274

	data Config =
	Config
	{ hlintOn :: Bool
	, diagnosticsOnChange :: Bool
	, maxNumberOfProblems :: Int
	, diagnosticsDebounceDuration :: Int
	, liquidOn :: Bool
	, completionSnippetsOn :: Bool
	, formatOnImportOn :: Bool
	, formattingProvider :: T.Text
	} deriving (Show,Eq)

[googleson78]

Thanks! This would be great! relating #432, as it is somewhat a start on this.