feat(ruby): Add basic support for displaying dbg variables (#125)

Adds support for displaying variables with a debugger attached.

## Screenshots

![CleanShot 2025-06-29 at 07 37
25@2x](https://github.com/user-attachments/assets/d3f6f7d5-d3a9-45d0-ac82-4db22b2434ce)

Author: vitallium

languages/ruby/debugger.scm

@@ -0,0 +1,13 @@
+(assignment left: (identifier) @debug-variable)
+(assignment left: (call receiver: (identifier) @debug-variable))
+(assignment left: (call method: (identifier) @debug-variable))
+(call (argument_list (call receiver: (identifier) @debug-variable)))
+(call (argument_list (call method: (identifier) @debug-variable)))
+
+(call (argument_list (identifier) @debug-variable))
+
+(method (method_parameters) @debug-variable)
+(body_statement (assignment (instance_variable) @debug-variable))
+
+(program) @debug-scope
+(body_statement) @debug-scope