implement game configuration file

this integrates https://github.com/cktan/tomlc99 into the repo as a dependency

third-party/tomlc99/.editorconfig

@@ -0,0 +1,14 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = false
+trim_trailing_whitespace = true
+
+[*.{c,h}]
+indent_style = space
+indent_size = 2
+
+[Makefile]
+indent_style = tab
+indent_size = 4