#3231 step 1: Annotate Usages Of Config Classes

[alex-courtis]

follows #2934

Apply ---@type and ---@param for all usages of nvim_tree.config classes.

This may be problematic:

• All fields are all marked optional (for the user) however we assume they are all present following merge_options
• Classes are not strict

A quick experiment reveals that this is a problem for Renderer.
Pragmatic: Change all Config fields to mandatory

• They are not (exact) classes
• config is always fully populated at runtime
• Defaults are always documented

Stretch: for modules not covered by step 4, rename all opts to config or c as it is confusing.