Update readme with list of new functions

Author: AJenbo

README.md

@@ -6,11 +6,44 @@ A PHP Language Server Protocol (LSP) implementation in Rust.
 
 ## Features
 
-- LSP lifecycle management (initialize, shutdown, document sync)
-- Basic completion
+### Document Synchronization
+
+- Full text document sync (open, change, close)
+
+### Completion
+
+- Instance member completion via `->` (methods and properties)
+- Static member completion via `::` (static methods, static properties, and constants)
+- `parent::` completion (static and non-static members, excluding private)
+- `$this`, `self`, and `static` keyword resolution to the current class
+- Property chain resolution (e.g. `$this->service->`)
+- Variable type resolution from assignments (`$var = new Foo()`) and parameter type hints
+- Inheritance-aware completion — walks the class hierarchy to include inherited members
+- Magic method filtering (`__construct`, `__destruct`, etc. are excluded from results)
+- Full method signature display in completion labels (parameters, types, return type)
 
 <img width="683" height="339" alt="image" src="https://github.com/user-attachments/assets/65e8220d-5d94-466f-aea7-2f239a8d4b19" />
 
+### Go to Definition
+
+- Jump to class, interface, trait, and enum definitions
+- Same-file and cross-file definition lookup
+- Fully-qualified, partially-qualified, and unqualified name resolution via `use` statements and the current namespace
+
+### PHP Parsing
+
+- Extracts classes, interfaces, methods, properties, and constants
+- Parses visibility modifiers, static modifiers, type hints, and parameter info
+- Supports constructor-promoted properties
+- Parses `use` statements and namespace declarations
+
+### Composer / PSR-4 Integration
+
+- Parses `composer.json` for PSR-4 autoload mappings (`autoload` and `autoload-dev`)
+- Parses vendor autoload mappings from `vendor/composer/autoload_psr4.php`
+- On-demand class loading from disk via PSR-4 resolution
+- Caches parsed files to avoid redundant parsing
+
 ## Building
 
 ```bash