Allow hooks for eglot initializationOptions about eglot-java

[yveszoundi]

Maybe.a function is desirable instead of a custom variable (e.g., eglot-java-initialization-options).

What if the user wants to dynamically configure LSP workspaceFolders based on project root details?

[yveszoundi]

From a documentation standpoint, users also need to understand 2 points:

• What is the LSP initialization request syntax from an emacs perspective?
• What are the available LSP server settings that can be initialized?

Emacs initialization request syntax

• Users need to understand the key elements of the iniialization request sent to the LSP server
• Users need to understand that the initialization request is a property list with keys set as keywords
  • Key syntax: :key (e.g., :java)
  • Key entry example: (:java (:home "/usr/share/jdk21"))
  • Instead of curly braces in JSON, you use parenthesis for "child objects"
  • For boolean false values, you use :json-false instead of nil, and t for true.

LSP initialization request settings

Users can customize several LSP server settings for the Eclipse JDT LS server.

• General summary and list of extended capabilities
• Available settings (names and data types)

[yveszoundi]

The eglot-workspace-configuration variable (buffer local) also seems to be a viable approach, but limited too.

• Defaults can be set via setq-default
• For project-specific configuration, values can be customized with directory local variables

eglot-workspace-configuration only impacts the settings node of the LSP configuration.
There are 4 overall top-level nodes for the LSP configuration:

• settings: Java LS configuration settings
• bundles: Optional list of Java jar bundles for LSP extensions
• workspaceFolders: a list of workspace folders (as URIs)
• extendedClientCapabilities: Java LS settings outside the scope of the LSP specification

[yveszoundi]

Addressed in commit dfd2755