.gitignore: Ignore build artefacts (#31)

- `*.mod` Module files
- `*.o` Object files
- library files

Author: jjokella

.gitignore

@@ -0,0 +1,8 @@
+include/*.mod
+interface/framework/*.mod
+interface/framework/*.o
+interface/model/*.mod
+interface/model/*.o
+lib/lib*
+src/*.mod
+src/*.o