Rename python renderer to plugin example and leave it be as a template

plugins/plugin-example/src/plugin-main.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <glib.h>
+#include <gds-render/gds-utils/gds-types.h>
+#include <gds-render/output-renderers/external-renderer-interfaces.h>
+
+int FUNC_DECL(EXTERNAL_LIBRARY_RENDER_FUNCTION)(struct gds_cell *toplevel, GList *layer_info_list, const char *output_file_name, double scale)
+{
+	if (!toplevel)
+		return -1000;
+
+	printf("Rendering %s\n", toplevel->name);
+	return 0;
+}
+
+int FUNC_DECL(EXTERNAL_LIBRARY_INIT_FUNCTION)(const char *params, const char *version)
+{
+	printf("Init with params: %s\ngds-render version: %s\n", params, version);
+	return 0;
+}