Fix outdated docs: variadic/va_list, skippable symbol types, typos.

- c/filtering.md: variadic functions are now supported; va_list is what's skipped
- configuration.md: document that skip works for enums, typedefs, unions, variables
- c/c_bindings.md: note that va_list functions are skipped
- cpp/cpp_bindings.md: fix typos (addition→additional, wrapp→wrap)

Author: cfis

docs/c/c_bindings.md

@@ -105,7 +105,7 @@ end
 
 `ruby-bindgen` supports the following FFI features:
 
-- [Functions](https://github.com/ffi/ffi/wiki/Basic-Usage) - C functions mapped to Ruby module methods via `attach_function`, including variadic functions (`:varargs`)
+- [Functions](https://github.com/ffi/ffi/wiki/Basic-Usage) - C functions mapped to Ruby module methods via `attach_function`, including variadic functions (`:varargs`). Functions taking `va_list` parameters are skipped since `va_list` cannot be constructed from Ruby.
 - [Structs](https://github.com/ffi/ffi/wiki/Structs) - C structs mapped to `FFI::Struct` classes with proper layouts
 - Unions - C unions mapped to `FFI::Union` classes
 - [Enums](https://github.com/ffi/ffi/wiki/Enums) - C enums mapped to FFI enum types

docs/c/filtering.md

@@ -15,6 +15,6 @@ See [`symbols`](../configuration.md#symbols) in the configuration documentation.
 The following are automatically skipped:
 
 - **Deprecated**: Functions marked with `__attribute__((deprecated))` or `[[deprecated]]`
-- **Variadic**: Functions with `...` parameters (cannot be called via FFI)
+- **va_list**: Functions taking `va_list` parameters (cannot be constructed from Ruby; use the variadic `...` version instead)
 - **Private/Protected**: Non-public members
 - **System headers**: Declarations from system include paths

docs/configuration.md

@@ -140,11 +140,11 @@ The `symbols` option groups per-symbol actions and name mappings by type. The ac
 
 ### Skip
 
-The `skip` key lists symbols to exclude from bindings. This is useful when:
+The `skip` key lists symbols to exclude from bindings. This works for functions, classes, enums, typedefs, unions, and variables. This is useful when:
 
-- Functions have export macros but still aren't available (build configuration issues)
-- Functions are internal/private APIs not meant for external use
-- Functions cause linker errors due to missing symbols
+- Symbols have export macros but still aren't available (build configuration issues)
+- Symbols are internal/private APIs not meant for external use
+- Symbols cause linker errors due to missing definitions
 
 Symbol names support:
 
@@ -160,6 +160,9 @@ symbols:
     - cv::ocl::PlatformInfo::versionMinor    # Skips only this specific method
     - "cv::Mat_::zeros(int, const int *)"    # Skips only this overload (others remain)
     - /cv::dnn::.*Layer::init.*/             # Regex: skips all init* methods on any Layer class
+    - DeprecatedEnum                           # Skips an enum
+    - InternalUnion                            # Skips a union
+    - debugVariable                            # Skips a variable
 ```
 
 ### Versions

docs/cpp/cpp_bindings.md

@@ -139,9 +139,9 @@ target_precompile_headers(my_extension PRIVATE
 )
 ```
 
-You can specify a custom include file by setting the `include` option in the configuration file. This will replace the default `rice_include.hpp` file and thus allow you to specify your own `include` files if necessary. Your custom header must include the Rice headers, plus any addition includes or definitions you want to be global.
+You can specify a custom include file by setting the `include` option in the configuration file. This will replace the default `rice_include.hpp` file and thus allow you to specify your own `include` files if necessary. Your custom header must include the Rice headers, plus any additional includes or definitions you want to be global.
 
-For example, it is a good place to add support for custom smart pointers. For example, OpenCV defines `cv::Ptr<T>` which inherits from `std::smart_pointer<T>`. The opencv-ruby bindings wrapp this smart pointer in a custom header file that is then added to `rice_includes.hpp`. That means all translation units see it, preventing ODR violations.
+For example, it is a good place to add support for custom smart pointers. For example, OpenCV defines `cv::Ptr<T>` which inherits from `std::smart_pointer<T>`. The opencv-ruby bindings wrap this smart pointer in a custom header file that is then added to `rice_includes.hpp`. That means all translation units see it, preventing ODR violations.
 
 A custom include file will not be overwritten by `ruby-bindgen`.