patch 7.4.875

Problem:    Not obvious how to contribute.
Solution:   Add a remark about CONTRIBUTING.md to README.md

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    875,
 /**/
     874,
 /**/