docs: update Function and FunctionDeclaration class documentation

Author: SunBK201

docs/classes/scubatrace.Function.rst

@@ -3,4 +3,9 @@
 
 .. autoclass:: scubatrace.Function
    :members:
-   :show-inheritance:
+   :show-inheritance:
+
+
+.. autoclass:: scubatrace.FunctionDeclaration
+   :members:
+   :show-inheritance:

scubatrace/__init__.py

@@ -16,6 +16,6 @@
 from .parser import Parser
 
 from .file import File
-from .function import Function
+from .function import Function, FunctionDeclaration
 from .statement import Statement, SimpleStatement, BlockStatement
 from .identifier import Identifier