fix(lua): small lua / lau doc fixes (#2415)

* fix(lua): small lua / lau doc fixes: expose stats.get_character_index like intended. also add a bit of doc to button and sameline pages so that the user is correctly refered to the tab class doc

docs/lua/classes/button.md

@@ -3,4 +3,5 @@
 ## Inherit from 1 class: base_text_element
 
 Class representing a gui button.
+Refer to the tab class documentation for more info (tab:add_button(name, callback))
 

docs/lua/classes/sameline.md

@@ -1,4 +1,5 @@
 # Class: sameline
 
 Class for ImGui::SameLine() - Puts a sameline between widgets or groups to layout them horizontally.
+Refer to the tab class documentation for more info (tab:add_sameline())
 

src/lua/bindings/gui/button.hpp

@@ -8,6 +8,7 @@ namespace lua::gui
 	// Name: button
 	// Inherit: base_text_element
 	// Class representing a gui button.
+	// Refer to the tab class documentation for more info (tab:add_button(name, callback))
 	class button : public base_text_element
 	{
 		sol::protected_function m_callback;

src/lua/bindings/gui/sameline.hpp

@@ -6,6 +6,7 @@ namespace lua::gui
 	// Lua API: Class
 	// Name: sameline
 	// Class for ImGui::SameLine() - Puts a sameline between widgets or groups to layout them horizontally.
+	// Refer to the tab class documentation for more info (tab:add_sameline())
 	class sameline : public gui_element
 	{
 	public:

src/lua/bindings/stats.cpp

@@ -277,6 +277,8 @@ namespace lua::stats
 	{
 		auto ns = state["stats"].get_or_create<sol::table>();
 
+		ns["get_character_index"] = get_character_index;
+
 		ns["get_bool"]        = sol::overload(get_bool_hash, get_bool_name);
 		ns["get_bool_masked"] = sol::overload(get_bool_masked_hash, get_bool_masked_name);
 		ns["get_float"]       = sol::overload(get_float_hash, get_float_name);