Write Autotools configuration

Add Autotools configuration files for building binaries.

.gitignore

@@ -1,2 +1,41 @@
+# Only include required source files.
+# Do no include any binaries or libraries/external sources.
+# Submodules are not added here, as they are managed by Git automatically.
+*
+*/
+
+# /
+!.gitignore
+!.gitignores
+!AUTHORS
+!build.sh
+!CHANGELOG
+!configure.ac
+!LICENSE
+!Makefile.am
+!README
+!TODO
+
+# /docs
+!/docs/
+/docs/*
+
+!/docs/1.O_LEGAL
+/docs/1.0_LEGAL/*
+
+!/docs/1.0_LEGAL/1.1_PRIVACY
+
+# /src
+!/src/
+/src/*
+
+!/src/gdextension_interface.h
+!/src/Makefile.am
+!/src/main.c
+!/src/main.gdextension
+!/src/main.h
+
 # Godot 4+ specific ignores
 .godot/
+
+